GTP: convert from translation port to dual faced port

I spent numerous hours in trying to avoid the dual faced port from
segfaulting, but in the end didn't succeed :(

The easy way was then simply to fall back to the known-working pattern
of the dual-faced port, which I already successfully used also on the NS
module for the Gb Inteface
diff --git a/ggsn_tests/regen_makefile.sh b/ggsn_tests/regen_makefile.sh
index 2668873..e73452d 100755
--- a/ggsn_tests/regen_makefile.sh
+++ b/ggsn_tests/regen_makefile.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-FILES="*.ttcn IPL4asp_PT.cc  IPL4asp_discovery.cc  TCCConversion.cc  TCCInterface.cc GTPC_EncDec.cc GTPU_EncDec.cc GTP_CodecPort_CtrlFunctDef.cc GTPC_PT.cc GTPU_PT.cc"
+FILES="*.ttcn IPL4asp_PT.cc  IPL4asp_discovery.cc  TCCConversion.cc  TCCInterface.cc GTPC_EncDec.cc GTPU_EncDec.cc GTP_CodecPort_CtrlFunctDef.cc"
 
 ttcn3_makefilegen -f GGSN_Tests.ttcn $FILES
 sed -i -e 's/# TTCN3_DIR = /TTCN3_DIR = \/usr/' Makefile