Update strings.json (#41293)

homeassistant/components/local_ip/strings.json

@@ -10,7 +10,7 @@
       }
     },
     "abort": {
-      "single_instance_allowed": "Only a single configuration of Local IP is allowed."
+      "single_instance_allowed": "[%key:common::config_flow::abort::single_instance_allowed%]"
     }
   }
 }