check MessageId doesn't owerflow 65535 (moquette-io#586)

Message ID should always be in the range 1 - 65535. This adds limited to test,
and, and resets the counter to 1 when needed

Fixes moquette-io#585

broker/src/main/java/io/moquette/broker/MQTTConnection.java

@@ -512,7 +512,7 @@ public void resendNotAckedPublishes() {
     }
 
     int nextPacketId() {
-        return lastPacketId.incrementAndGet();
+        return lastPacketId.updateAndGet(v -> v == 65535 ? 1 : v + 1);
     }
 
     @Override

broker/src/test/java/io/moquette/broker/MQTTConnectionConnectTest.java

@@ -319,4 +319,13 @@ public void testForceClientDisconnection_issue116() {
         assertFalse(channel.isOpen(), "First 'FAKE_CLIENT_ID' channel MUST be closed by the broker");
         assertTrue(anotherChannel.isOpen(), "Second 'FAKE_CLIENT_ID' channel MUST be still open");
     }
+
+    @Test
+    public void testMessageIdGeneration() {
+        for (int i = 0; i < 65_536; i++) {
+            int nextPacketId = sut.nextPacketId();
+            assertTrue(nextPacketId > 0, "Packet ID must be > 0");
+            assertTrue(nextPacketId <= 65_535, "Packet ID must be <= 65_535");
+        }
+    }
 }