fix: repeatedly adding instance to the instance watcher

module/instance_watcher.py

@@ -57,6 +57,8 @@ class InstanceWatcher:
             self.remove_instance(i)
 
     def try_add_instance(self, name):
+        if name in self.instances:
+            return
         config = AzurLaneConfig(name)
         full_config = config.full_config
         if full_config.Restart_InstanceRestart_Enable: