Hi
When pgAdmin4 runs in DEBUG mode, Flask initialise service twice, while in
non-DEBUG mode, once. It is pain while development because `yarn run
bundle` also runs twice.
It is because the parameter `use_reloader` = True in Debug Mode.
If `os.environ` variable `WERKZEUG_RUN_MAIN` is set to None, i.e. app is
starting for the first time and then its value is changed to True.
Please find attached patch.
Thanks
Surinder