capmt: adjust for recent OSCam frame change

Additional byte describing adapter index was
added to the beginning of the frame.
It only affect tvh capmt mode 2.
Merge remote-tracking branch 'origin/pr/311'
capmt: attempt to avoid confusion over validity of configuration

UI now has 3 possible colours, red - not working, orange - not connected
(but will probably work, used for new non-persistent mode 2) and green -
actively connected.