ggsn: Introduce test TC_pdp46_act_deact_apn4

Related osmo-ggsn.git libgtp fix: I6c6215a4ce478afabc78ffaf5ffb0cf829e41226

Related: OS#4154
Change-Id: Ia1893e0c181307ac1ceb07ee5f496507f7a603c8
diff --git a/ggsn_tests/expected-results.xml b/ggsn_tests/expected-results.xml
index e57a7df..374cde0 100644
--- a/ggsn_tests/expected-results.xml
+++ b/ggsn_tests/expected-results.xml
@@ -21,6 +21,7 @@
   <testcase classname='GGSN_Tests' name='TC_pdp46_act_deact_pcodns6' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp46_act_deact_gtpu_access' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp46_clients_interact' time='MASKED'/>
+  <testcase classname='GGSN_Tests' name='TC_pdp46_act_deact_apn4' 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>