Fix executing disable barbs command when player isn't OP (#2864)

Stops the disable barbarian command being executed if the player isn't opped

src/main/java/com/minecolonies/coremod/commands/colonycommands/DisableBarbarianSpawnsCommand.java

@@ -102,6 +102,7 @@ private void executeShared(@NotNull final MinecraftServer server, @NotNull final
         if (sender instanceof EntityPlayer && !isPlayerOpped(sender))
         {
             sender.sendMessage(new TextComponentString("Must be OP to use this command"));
+            return;
         }
 
         colony.getBarbManager().setCanHaveBarbEvents(canHaveBarbEvents);