Allow right click actions in the lobby.

Originally, the right click ban was introduced to prevent issues with people blowing themselves and each other up in the lobby. The right click ban only solves this issue sometimes, so it isn't really very effective.

By removing the right click ban, it becomes possible to activate redstone stuff like buttons and levers in the lobby.

Fixes #431.

src/main/java/com/garbagemule/MobArena/ArenaListener.java

@@ -1065,13 +1065,6 @@ public class ArenaListener
         Player p = event.getPlayer();
         if (!arena.inLobby(p)) return;
 
-        // Player is in the lobby, so disallow using items.
-        Action a = event.getAction();
-        if (a == Action.RIGHT_CLICK_AIR || a == Action.RIGHT_CLICK_BLOCK) {
-            event.setUseItemInHand(Result.DENY);
-            event.setCancelled(true);
-        }
-
         // Bail if off-hand or if there's no block involved.
         if (event.getHand() == EquipmentSlot.OFF_HAND || !event.hasBlock())
             return;