#2725 (Oct 22, 2020, 1:01:46 PM)

sysmocom: emergency_preemptive_call.py: Avoid test failure if 2nd call not fully established

It may happen that the non-emergency call MT leg is still not properly
released when the emergency call MT leg is to be assigned a TCH, meaning
BSC will fail with an Assignment Failure upon Assignment request from
MSC.
The test sometimes passed and sometimes didn't, due to above mentioned
race condition. Let's relax a bit the test expectancies to have it
always passing, while still verifying preemption happens, and MT phone
is reached.

Related: OS#4549
Change-Id: I3697227cac56a1327f9ea08c5c2f52568e8d2a8a