Fixed a warning. Seriously, guys...

src/main/java/com/sk89q/worldedit/WorldEditPermissionException.java

@@ -4,6 +4,8 @@ package com.sk89q.worldedit;
  * @author zml2008
  */
 public class WorldEditPermissionException extends WorldEditException {
+    private static final long serialVersionUID = 1L;
+
     public WorldEditPermissionException() {
         super("You don't have permission to do this.");
     }