Discovery changes / fixes

[Consti10]

This changes the default behaviour during discovery slightly
Should fix both the

1. "no wifi hotspot created" if no air wb card is found
   and
2. "ground does not reliably detect 2 rx card(s) (diversity)"

Issues.
Air waits for 1 wb capable card (or timeout after 10seconds without wb functionality)
Ground waits for 2 wb capable cards (or timeout after 10seconds without wb functionality).

10 Seconds should be enough to catch 2 cards, if they are connected and powered properly.

Increases ground boot up time by 10 seconds for single card users though