session: update due to clib_socket refactoring

After the clib_socket_init syntax changed, the behavior of VCL
socket creation was broken. This patch introduces app_namespace_add_del_v4
to address the behavioral change.

Type: refactor

Change-Id: Ice016bdb372233fd3317f166d45625e086e9b4df
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
diff --git a/src/vnet/session/session_test.c b/src/vnet/session/session_test.c
index 13970d5..770e726 100644
--- a/src/vnet/session/session_test.c
+++ b/src/vnet/session/session_test.c
@@ -325,6 +325,18 @@
 }
 
 static void
+vl_api_app_namespace_add_del_v4_reply_t_handler (
+  vl_api_app_namespace_add_del_v4_reply_t *mp)
+{
+}
+
+static int
+api_app_namespace_add_del_v4 (vat_main_t *vat)
+{
+  return -1;
+}
+
+static void
 vl_api_app_namespace_add_del_v3_reply_t_handler (
   vl_api_app_namespace_add_del_v3_reply_t *mp)
 {