fix: Show helpful message when no supported updater loads

[ryanalexander]

Fixes #3282

Currently ProtocolLib sends the following when loading on a server which does not implement the spigot config.

[22:13:24] [Server thread/ERROR]: [ProtocolLib] INTERNAL ERROR: Cannot perform automatic updates. If this problem hasn't already been reported, please open a ticket at https://github.com/dmulloy2/ProtocolLib/issues with the following data: Stack Trace: java.lang.NullPointerException: Cannot invoke "com.comphenix.protocol.updater.Updater.isChecking()" because "this.updater" is null at com.comphenix.protocol.ProtocolLib.checkUpdates(ProtocolLib.java:514) at com.comphenix.protocol.ProtocolLib.lambda$createPacketTask$0(ProtocolLib.java:485) at org.bukkit.craftbukkit.v1_21_R1.scheduler.CraftTask.run(CraftTask.java:77) at org.bukkit.craftbukkit.v1_21_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:414) at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:1388) at net.minecraft.server.dedicated.DedicatedServer.c(DedicatedServer.java:393) at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1290) at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1040) at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:310) at java.base/java.lang.Thread.run(Thread.java:1583) Dump: manager: com.comphenix.protocol.injector.PacketFilterManager@62afb16b[ plugin=ProtocolLib v5.3.0-SNAPSHOT-732 server=CraftServer{serverName=Pebble,serverVersion=git-Bukkit-19bf846,minecraftVersion=1.21.1} reporter=com.comphenix.protocol.ProtocolLib$1@299584bc minecraftVersion=(MC: 1.21.1) asyncFilterManager=com.comphenix.protocol.async.AsyncFilterManager@392ce8e6 pluginVerifier=com.comphenix.protocol.injector.PluginVerifier@26972241 mainThreadPacketTypes=com.comphenix.protocol.concurrent.PacketTypeListenerSet@7c94b48d inboundListeners=com.comphenix.protocol.injector.collection.InboundPacketListenerSet@79217fc7 outboundListeners=com.comphenix.protocol.injector.collection.OutboundPacketListenerSet@2714d3dd registeredListeners=[PacketAdapter[plugin=DeluxeCombat, sending=ListeningWhitelist[priority=NORMAL, packets=[WORLD_PARTICLES[class=PacketPlayOutWorldParticles, id=41]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=DeluxeCombat, sending=ListeningWhitelist[priority=NORMAL, packets=[ENTITY_VELOCITY[class=PacketPlayOutEntityVelocity, id=90]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=Citizens, sending=ListeningWhitelist[priority=HIGHEST, packets=[ENTITY_METADATA[class=PacketPlayOutEntityMetadata, id=88]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=DeluxeCombat, sending=ListeningWhitelist[priority=NORMAL, packets=[NAMED_SOUND_EFFECT[class=PacketPlayOutNamedSoundEffect, id=104]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=WorldGuardExtraFlags, sending=ListeningWhitelist[priority=NORMAL, packets=[REMOVE_ENTITY_EFFECT[class=PacketPlayOutRemoveEntityEffect, id=67]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=Skyblock, sending=ListeningWhitelist[priority=NORMAL, packets=[SPAWN_ENTITY[class=PacketPlayOutSpawnEntity, id=1]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=Citizens, sending=ListeningWhitelist[priority=HIGHEST, packets=[PLAYER_INFO[class=ClientboundPlayerInfoUpdatePacket, id=62]], gamephase=PLAYING, options=[ASYNC]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=Citizens, sending=ListeningWhitelist[priority=HIGHEST, packets=[ENTITY_HEAD_ROTATION[class=PacketPlayOutEntityHeadRotation, id=72], REL_ENTITY_MOVE_LOOK[class=PacketPlayOutRelEntityMoveLook, id=47], ENTITY_LOOK[class=PacketPlayOutEntityLook, id=48], ENTITY_TELEPORT[class=PacketPlayOutEntityTeleport, id=112]], gamephase=PLAYING, options=[ASYNC]], receiving=EMPTY_WHITELIST]] networkManagerInjector=com.comphenix.protocol.injector.netty.manager.NetworkManagerInjector@388e6854 debug=false closed=false injected=true ] Sender: com.comphenix.protocol.ProtocolLib@13ca17a8[ statistics=com.comphenix.protocol.metrics.Statistics@1241a437 packetTask=com.comphenix.protocol.scheduler.DefaultTask@5946a2e3 tickCounter=20 configExpectedMod=1 updater=<null> redirectHandler=com.comphenix.protocol.ProtocolLib$2@4e4f5ec scheduler=com.comphenix.protocol.scheduler.DefaultScheduler@47d0d58f commandProtocol=com.comphenix.protocol.CommandProtocol@58afa15e commandPacket=com.comphenix.protocol.CommandPacket@34124112 commandFilter=com.comphenix.protocol.CommandFilter@177a89e9 packetLogging=com.comphenix.protocol.PacketLogging@56c74a24 skipDisable=false isEnabled=true loader=org.bukkit.plugin.java.JavaPluginLoader@7347b4f3 server=CraftServer{serverName=Pebble,serverVersion=git-Bukkit-19bf846,minecraftVersion=1.21.1} file=plugins/ProtocolLib.jar description=org.bukkit.plugin.PluginDescriptionFile@557b7158 dataFolder=plugins/ProtocolLib classLoader=org.bukkit.plugin.java.PluginClassLoader@4b6eca77 naggable=true newConfig=YamlConfiguration[path='', root='YamlConfiguration'] configFile=plugins/ProtocolLib/config.yml logger=org.bukkit.plugin.PluginLogger@7af77150 ] Version: ProtocolLib v5.3.0-SNAPSHOT-732 Java Version: 21.0.2 Server: git-Bukkit-19bf846 (MC: 1.21.1)