Remove local libgsupclient; Use libosmo-gsup-client from osmo-hlr

osmo-hlr has recently (as of Change-Id
Iad227bb477d64da30dd6bfbbe1bd0c0a55be9474) a working shared library
implementation of libosmo-gsup-client.

We can remove the local implementation in osmo-msc and use the
system-installed shared library instead.

Change-Id: I6f542945403cf2e3ddac419186b09ec0e2d43b69
diff --git a/src/libvlr/Makefile.am b/src/libvlr/Makefile.am
index 1408f6c..dcae1c7 100644
--- a/src/libvlr/Makefile.am
+++ b/src/libvlr/Makefile.am
@@ -5,6 +5,7 @@
 	   $(LIBOSMOVTY_CFLAGS) \
 	   $(LIBOSMOSCCP_CFLAGS) \
 	   $(LIBOSMOMGCPCLIENT_CFLAGS) \
+	   $(LIBOSMOGSUPCLIENT_CFLAGS) \
 	   $(LIBOSMOABIS_CFLAGS) \
 	   $(LIBOSMORANAP_CFLAGS) \
 	   $(COVERAGE_CFLAGS) \