DbTool: Add mysql context identifiers for the REFERENCES privilege

Though this privilege is not in use until mysql version 5.7.6 it is registered
as privilege in the privilege tables in earlier versions.

refs #8707

modules/setup/library/Setup/Utils/DbTool.php

@@ -78,7 +78,7 @@ class DbTool
         'INSERT'                    => 29,
         'LOCK TABLES'               => 5,
         'PROCESS'                   => 1,
-        'REFERENCES'                => 0,
+        'REFERENCES'                => 12,
         'RELOAD'                    => 1,
         'REPLICATION CLIENT'        => 1,
         'REPLICATION SLAVE'         => 1,