split off osmo-sgsn: remove files, apply build

Change-Id: I5d27ff93e56cd13e0e70edd15e2080201e35e91f
diff --git a/tests/gbproxy/Makefile.am b/tests/gbproxy/Makefile.am
index 2dd66df..3291839 100644
--- a/tests/gbproxy/Makefile.am
+++ b/tests/gbproxy/Makefile.am
@@ -40,9 +40,6 @@
 	$(top_builddir)/src/gprs/gprs_llc_parse.o \
 	$(top_builddir)/src/gprs/crc24.o \
 	$(top_builddir)/src/gprs/gprs_utils.o \
-	$(top_builddir)/src/libcommon/libcommon.a \
-	$(top_builddir)/src/libbsc/libbsc.a \
-	$(top_builddir)/src/libtrau/libtrau.a \
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOGB_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
diff --git a/tests/gbproxy/gbproxy_test.c b/tests/gbproxy/gbproxy_test.c
index 577daa9..9672dcb 100644
--- a/tests/gbproxy/gbproxy_test.c
+++ b/tests/gbproxy/gbproxy_test.c
@@ -49,6 +49,8 @@
 
 #define MATCH_ANY (-1)
 
+void *tall_bsc_ctx;
+
 struct gbproxy_config gbcfg = {0};
 
 struct llist_head *received_messages = NULL;