BSSGP_Emulation: expect altstep timeout entry only if timer is running

Should fix the following log message:
BSSGP_Emulation.ttcnpp:1118 Timeout operation on timer g_T1 failed: The timer is not started.

Change-Id: Id7d1b76a6bc1fc2f0f4896c59673c01293b526e9
1 file changed