[find_orb] Bug fix : endless loop of (unhelpful) 'help' text

[Bill Gray]

Hello all,

    Peter Birtwhistle pointed out,  and I've fixed,  an annoying bug 
that worked as follows :

    Move the cursor over any observatory in the list of MPC codes at the 
bottom of the screen,  and you could scroll the mouse wheel up/down to 
find the previous/next observation from that code.  So far,  so good.

    But if you moved the cursor over,  say,  "Obs" in the residual 
legend,  or anything else that would show a tooltip/hint text,  you'd 
get stuck.  Moving the mouse would get a help screen for the MPC code 
area at the bottom of the screen.  Quit that,  move the mouse,  and 
you'd be back at the help screen.

    It turned out I'd committed a small act of programming stupidity, 
fortunately easily fixed.  Download the software again,  and you won't 
see that bug.

-- Bill