[mythtv] DVB: no longer paying attention to "Open DVB card on demand"?

[Dave Just]

I have the "open DVB card on demand" flag set, but it seems that in  
recent versions this flag is not obeyed?  I can see this on my USB  
DVB-T CinergyT2 as there is light indicating activity (or tuning  
lock, not sure what exactly).  Also, if I run mythtv-setup while the  
backend is running, I see "Could not open card #0!".  At least for  
the last reason, I think the on-demand behaviour should be the  
default, BTW, for least surprise.

  - Dave