HOTFIX: bug preventing usergroup manager from adding members to group linked to project

[deepsidhu85]

Description of changes

What did you change in this pull request? Provide a description of files changed, user interactions changed, etc. Include how to test your changes.

Fixed bug preventing a manager of a usergroup from adding members to via a project

To test:

Before Fix (on dev branch):

1. Create User A as user and User B as manager
2. As User B, create user group
3. As User A, create project and add User B as project collaborator. Also add usergroup created by User B above as collaborator
4. As User B, try to add user A as group member to group and it should fail (the UI will not do anything but if you look in the console in intellij/vscode/etc you should see an error in the stacktrace for a nullpointer exception

After Fix (this branch):

1. Create User A as a user and User B as manager
2. As User B, create user group
3. As User A, create project and add User B as project collaborator. Also, add usergroup (project settings -> user groups) created by User B above and set role as collaborator
4. As User B, try to add user A as group member to group and it should succeed and there should be no error in the intellij/vscode/etc console.

Related issue

Link to the GitHub issue this pull request addresses using the #issuenum format. If it completes an issue, use Fixes #issuenum to automatically close the issue.

Checklist

Things for the developer to confirm they've done before the PR should be accepted:

• CHANGELOG.md (and UPGRADING.md if necessary) updated with information for new change.
• Tests added (or description of how to test) for any new features.
  * [ ] User documentation updated for UI or technical changes.

[ericenns]

👍 This is now working as expected, thanks!