Add proper message when user opens challenges gui in world without a challenges.

src/main/java/world/bentobox/challenges/panel/user/ChallengesGUI.java

@@ -73,10 +73,10 @@ public class ChallengesGUI extends CommonGUI
 	public void build()
 	{
 		// Do not open gui if there is no challenges.
-		if (this.challengesManager.getAllChallenges(this.world).isEmpty())
+		if (!this.challengesManager.hasAnyChallengeData(this.world))
 		{
 			this.addon.getLogger().severe("There are no challenges set up!");
-			this.user.sendMessage("general.errors.general");
+			this.user.sendMessage("challenges.errors.no-challenges");
 			return;
 		}
 

src/main/resources/locales/en-US.yml

@@ -358,6 +358,7 @@ challenges:
         exist-challenges-or-levels: '&cIn your world already exist challenges. Cannot proceed!'
         defaults-file-exist: '&cdefault.json already exists. Use overwrite mode to replace it!'
         defaults-file-error: '&cThere was an error while creating default.json file! Check console!'
+        no-challenges: '&cChallenges are not implemented in current world!'
 protection:
     flags:
         CHALLENGES_ISLAND_PROTECTION: