TT#158003 add subscriber_location_mappings mode 'forward'

* mode enum column now contains a new value 'forward' to reflect
  the database change.

Change-Id: Ida161b4d71863f4fb5c42a388a0464a9948ca6a4
(cherry picked from commit 487a908c56)

lib/NGCP/Schema/Result/voip_subscriber_location_mappings.pm

@@ -37,7 +37,7 @@ __PACKAGE__->add_columns(
   {
     data_type => "enum",
     default_value => "replace",
-    extra => { list => ["add", "replace", "offline"] },
+    extra => { list => ["add", "replace", "offline", "forward"] },
     is_nullable => 0,
   },
   "to_username",