TC_si_sched_2ter_2bis BTS_Tests

Regression

Failing for the past 1 build since #2690

Took 8.9 sec (from Titan)

Stack Trace

"BTS_Tests.ttcn:4595 : Error: Insufficient SI in array: 3 < 4"
      BTS_Tests.ttcn:9462 BTS_Tests control part
      BTS_Tests.ttcn:4964 TC_si_sched_2ter_2bis testcase