bsc: Add module param to disable osmux (fix bsc-latest jenkins job)

ttcn3-bsc-test-latest currently fails on most tests because it tries to
use "osmux off" VTY param and only current osmo-bsc master supports it.

Change-Id: I61e4c59b2926f3f70cb6d0190a8683861e54179a
1 file changed