TC_sabm_incorrect_c BTS_Tests_LAPDm:hopping

Failing for the past 337 builds since #2735

Took 23 sec (from Titan)

Stack Trace

"BTS_Tests.ttcn:732 : Tguard timeout"
      BTS_Tests_LAPDm.ttcn:1494 BTS_Tests_LAPDm control part
      BTS_Tests_LAPDm.ttcn:1341 TC_sabm_incorrect_c testcase