Simplify code at a few places

Remove some duplicate checks,
and unnecessary errors.
What I did not understand earlier was why we never see this error, when loading replies. Now I understand that mostly, we keep `selectedTargets` set to an empty array, which is fine. However, initially it's initiated to null. So we only hit this in extreme cases when the first thing that happens is loading a reply to a deleted annotation.

>  We should just skip the for loop here if there are no targets.

Yes.