only remove if lane_idx exist in closed_lanes (#276)

Signed-off-by: will <[email protected]>

Author: piliwilliam0306

rmf_demos_fleet_adapter/rmf_demos_fleet_adapter/fleet_adapter.py

@@ -456,7 +456,8 @@ def lane_request_cb(msg):
             closed_lanes.add(lane_idx)
 
         for lane_idx in msg.open_lanes:
-            closed_lanes.remove(lane_idx)
+            if lane_idx in closed_lanes:
+                closed_lanes.remove(lane_idx)
 
         state_msg = ClosedLanes()
         state_msg.fleet_name = fleet_name