Bug fix for changing message area with lightbar

Bug fix: When changing to another area with the lightbar interface, if the user's current sub-board is a high-numbered sub-board and they select a message group with fewer sub-boards, the highlighted sub-board in that group would be set to that high number and would be incorrect. That has been fixed. Copied a fix from my stand-alone message area chooser. In that scenario, the current highlighted sub-board in the other group will be the first one.