TC_pdp_act2_recovery GGSN_Tests

Failing for the past 496 builds since #958

Took 4.5 sec (from osmo-ttcn3-hacks_ggsn_tests)

Stack Trace

"GGSN_Tests.ttcn:383 : pingpong T_default timeout"
      GGSN_Tests.ttcn:2467 GGSN_Tests control part
      GGSN_Tests.ttcn:1973 TC_pdp_act2_recovery testcase