Remove group labels when sharing with groups is not allowed

[PVince81]

Steps to reproduce

1. Check out Dav respect disallow sharing with groups server#25658
2. Disallow sharing with groups in the sharing settings
3. Create a conversation
4. Type in the name of a group

Expected behaviour

No section about groups appears in the result.
No mention of "groups" in the placeholder.

Actual behaviour

Empty section about groups appears in the result.
Mention of "groups" in the placeholder.

Talk app

Talk app version: master