Group with just one client can't be unmuted

[cpegel]

Snapweb hides the mute/unmute icon for groups with a single client, rendering it impossible to unmute such groups when they have been muted using other control clients.

I guess the idea was that in this case just muting/unmuting the client itself suffices. However, other control clients such as Iris for Mopidy mute groups with single clients using the groups volume, not the clients volume.

In Snapdroid the behaviour is to hide the icon for singleton groups only when the group is unmuted, so these groups can at least be unmuted but not muted again.

Maybe this should ideally be solved in the snapserver by synchronizing mute/unmute status of group and client in the situation of just one client in a group?

[cpegel]

There's a related issue posted for Iris.