Fix bug introduced in Id3d1e92c7db813911b4bf4f27b92d4eff92bdd41 that stops actions actually being deleted.

Change-Id: If6e8325a94b5796df6a08d63e2d1d6b69364da55
Reviewed-on: http://gerrit.dmdirc.com/2630
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

src/com/dmdirc/actions/ActionGroup.java

         Logger.assertTrue(actions.contains(action));
 
         ActionManager.getActionManager().removeAction(action);
+        action.delete();
     }
 
     /**