fix: Fix Exception in Dynmap integration on empty claimed regions (#41)

* this should fix dynmap related error reported on discord
try/catch to handle possible NoSuchElementException when iterating claimed regions and added null check in DynmapManager

* attempt to make requested changes
replaced try/catch with if/else and import explicitly

src/main/java/com/craftaro/ultimateclaims/claim/Claim.java

@@ -28,12 +28,12 @@
 import org.bukkit.entity.Player;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
+import java.util.Collections;
+
 import java.util.concurrent.ThreadLocalRandom;
 
 public class Claim {
@@ -91,7 +91,11 @@ public int getId() {
     }
 
     public ClaimedChunk getFirstClaimedChunk() {
-        return this.claimedRegions.iterator().next().getFirstClaimedChunk();
+        if (!this.claimedRegions.isEmpty()) {
+            return this.claimedRegions.iterator().next().getFirstClaimedChunk();
+        } else {
+            return null;
+        }
     }
 
     public String getName() {

src/main/java/com/craftaro/ultimateclaims/dynmap/DynmapManager.java

@@ -56,8 +56,8 @@ public void refresh() {
 
         if (this.plugin.getClaimManager() != null) {
             for (Claim claim : this.plugin.getClaimManager().getRegisteredClaims()) {
-                if (Bukkit.getWorld(claim.getFirstClaimedChunk().getWorld()) == null) {
-                    continue;
+                if (claim.getFirstClaimedChunk() != null && Bukkit.getWorld(claim.getFirstClaimedChunk().getWorld()) == null) {
+                   continue;
                 }
 
                 if (claim.getCorners() != null) {