no error when client not built

jass/server.py

 #!/usr/bin/env python3
+import logging
 import os
 from pathlib import Path
 from typing import List
@@ -26,7 +27,10 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-app.mount("/webui", util.SinglePageApplication(directory=Path('client/dist')), name="SPA")
+if os.path.exists('client/dist'):
+    app.mount("/webui", util.SinglePageApplication(directory=Path('client/dist')), name="SPA")
+else:
+    logging.info("/webui cannot be served as client/dist is missing, please build the client.")
 
 
 @app.get("/")