Unpin voice room server for empty voice channel

Voice room server is currently being pinned forever automatically by first joined user in channel depending on their closest region. Communities can have people from all around the world and when people from other continent join that same channel when it was empty they will connect to the server that is very far away from them because it was pinned by the first user.

Unpin voice room server from voice channel when the channel is empty/last user leaves, so new people next day can automatically get the closest server.