If we have a leak, reset occupied value so that FindOccupiedClusters can be re-entered later for areas

qbsp/outside.cc

@@ -498,6 +498,9 @@ bool FillOutside(node_t *node, const int hullnum)
             exit(1);
         }
 
+        // clear occupied state, so areas can be flooded in Q2
+        ClearOccupied_r(node);
+
         return false;
     }