fix: correct indentation in _save_providers no-op comment

app/index.py

@@ -1154,7 +1154,7 @@ def _save_providers():
     #     with open(PROVIDERS_FILE, "w") as f:
     #         json.dump(_dynamic_providers, f, indent=2)
     # except Exception as e:
-        logger.warning("Failed to save providers: %s", e)
+    #     logger.warning("Failed to save providers: %s", e)
 
 
 def _register_provider_in_upstreams(prov: dict):