Small fix to selection set / multitarget / hotkey wing behavior. If a set is not active and something is targeted that is in a set, pressing THAT set's key will not change targets, but just activate the set.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@9680 387891d4-d844-0410-90c0-e4c51a9137d3