Fix offline worlds showing population of 65535

The service has been updated to return -1 when worlds are offline, and then the UI updated to display OFF when the count is less than 0

http-service/src/main/java/net/runelite/http/service/worlds/WorldsService.java

@@ -74,7 +74,7 @@ public class WorldsService
 				.address(readString(buf))
 				.activity(readString(buf))
 				.location(buf.get() & 0xFF)
-				.players(buf.getShort() & 0xFFFF);
+				.players(buf.getShort());
 
 			worlds.add(worldBuilder.build());
 		}