If the user has selected somebody other than themselves to chat with, we'll exclude the viewer from the results.
In other words, we'll only show the viewer as an option to themselves when the list is empty.
We're doing this because we want to treat this case similarly to when the viewer selects a non-friend: instead of letting them include themselves in the list, we will just open directly to the PRIVATE if the user select themselves at the start (D13545), and not list them as an option if they select somebody else at the start (this diff).
Depends on D13542