ggsn: Add TC_pdp4_act_deact_ipcp_pap_broken()

This test case reproduces a real-world PCO capture including a broken
PAP AuthenticationReq.  It triggers some weird behavior in OsmoGGSN
1.3.0 where it would send duplicate IPCP repsonses and no PAP response.

Change-Id: Ie89d984ed9e26fbbb2e4914bdb8623446d462a4c
Related: OS#3914
diff --git a/ggsn_tests/expected-results.xml b/ggsn_tests/expected-results.xml
index c2defea..c60a804 100644
--- a/ggsn_tests/expected-results.xml
+++ b/ggsn_tests/expected-results.xml
@@ -1,7 +1,8 @@
 <?xml version="1.0"?>
-<testsuite name='GGSN_Tests' tests='14' failures='1' errors='0' skipped='0' inconc='0' time='MASKED'>
+<testsuite name='GGSN_Tests' tests='15' failures='1' errors='0' skipped='0' inconc='0' time='MASKED'>
   <testcase classname='GGSN_Tests' name='TC_pdp4_act_deact' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp4_act_deact_ipcp' time='MASKED'/>
+  <testcase classname='GGSN_Tests' name='TC_pdp4_act_deact_ipcp_pap_broken' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp4_act_deact_pcodns' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp4_act_deact_gtpu_access' time='MASKED'/>
   <testcase classname='GGSN_Tests' name='TC_pdp4_clients_interact_with_txseq' time='MASKED'/>