Add SGs Interface

Add an SGs interface (3GPP TS 29.118) to osmo-msc in order to support
SMS tunneling and Circuit Switched Fallback (CSFB)

Change-Id: I73359925fc1ca72b33a1466e6ac41307f2f0b11d
Related: OS#3615
diff --git a/tests/msc_vlr/msc_vlr_test_no_authen.c b/tests/msc_vlr/msc_vlr_test_no_authen.c
index d52d3d6..df23011 100644
--- a/tests/msc_vlr/msc_vlr_test_no_authen.c
+++ b/tests/msc_vlr/msc_vlr_test_no_authen.c
@@ -22,6 +22,7 @@
  */
 
 #include "msc_vlr_tests.h"
+#include "stubs.h"
 
 static void test_no_authen()
 {