ggsn: Add test to verify retransmit queue_resp

Related: OS#3997
Change-Id: I8d937d0af9af8462418b174a54022655f9d77a5f
diff --git a/ggsn_tests/expected-results.xml b/ggsn_tests/expected-results.xml
index 081325e..c2defea 100644
--- a/ggsn_tests/expected-results.xml
+++ b/ggsn_tests/expected-results.xml
@@ -19,4 +19,5 @@
   <testcase classname='GGSN_Tests' name='TC_pdp6_act_deact_gtpu_access' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp6_clients_interact' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_echo_req_resp' time='MASKED'/>
+  <testcase classname='GGSN_Tests' name='TC_act_deact_retrans_duplicate' time='MASKED'/>
 </testsuite>