patch uvicorn run command

Author: chinosu

debugger2/src/serve.py

@@ -150,4 +150,4 @@ async def send_stdin(sid: str) -> None:
     info(" > ^ < ")
     info(f"Server is available at [http://{host}:{port}]")
 
-    run("server:app", port=port, host=host, log_level="error")
+    run("__main__:app", port=port, host=host, log_level="error")