User from groups are removed upon logout leaving with defult group

[slice-bharathk]

Issue Summary

We have created groups and added users under them. The moment the user connects and disconnects Redash, the allocated group is removed and the user has access to the default group only.

Redash Version: Version: 10.0.0 (9c928bd)

Steps to Reproduce

1. Create a new group and add data sources and members to it.
2. Ask the member to connect redash and disconnect.
3. Upon the next connection the user won't be able to see the data sources, because the user is removed from the group.

We need to add the user again to the group and it is repeating, we want the user not to get removed the group.

Technical details:

• Redash Version: Version: 10.0.0 (9c928bd)
• Browser/OS: Chrome/Linux
• How did you install Redash: Helm chart