Fix /xprate not properly sending "Event started" messages. Fixes #624

src/main/java/com/gmail/nossr50/mcMMO.java

@@ -540,5 +540,9 @@ public class mcMMO extends JavaPlugin {
     public void setXPEventEnabled(boolean enabled) {
         this.xpEventEnabled = enabled;
     }
+
+    public void toggleXpEventEnabled() {
+        xpEventEnabled = !xpEventEnabled;
+    }
 }