ttcn3/lib/testlib.py: increase test suite execution timeout

Since I8eb28584e90ad012cbf7f3175ee3a8e775c8d523, the test suite
is supposed to run both BTS_Tests_{SMSCB,LAPDm}.control among with
BTS_Tests.control.  Apparently this requires more time than 3600
seconds, so everything is broken since build #2652 in Jenkins.

Change-Id: Ieceab920a94cbf92ff6c83a59d572f22e8ae933f

sysmocom/ttcn3/suites/ttcn3_bts_tests/lib/testlib.py

@@ -36,7 +36,7 @@ def run_ttcn3(tenv, testdir, bts, osmocon, nat_rsl_ip,
     try:
         proc.launch()
         print('TTCN3 test suite launched, waiting until it finishes')
-        proc.wait(timeout=3600)
+        proc.wait(timeout=5400) # 1.5h
     except Exception as e:
         proc.terminate()
         raise e