Fix error when fetch app_id and/or secrets: ValueError: list.remove(x): x not in list (fix #751 #767 #752)

[wangw469]

fix #751
fix #752
fix #767

Fix error when fetch app_id and/or secrets:
ValueError: list.remove(x): x not in list

Try to fix this error by check if vals contains empty string:

        if "" in vals:
            vals.remove("")

[wangw469]

@nathom Thanks a lot for making such a great tool, I love it!

As a new user, I encounter this issue and it almost scare me away.
Since it will affect all user don't have app_id and secrets inside config file, maybe we can fix it and release a new version?

[nathom]

Looks good. Thanks!

[nathom]

@wangw469 I haven't got time to work on this for the past few months. I will test everything and make a public release in ~2 weeks.