TT#35053 Add index to both username,with

This is needed because we now also look at the `with` part
to also retrieve inbound messages to a user.

Change-Id: I8602ec4e3e8b94dcbdd3548dd3ad4ac73d399c0d

db_scripts/diff/15393.down

@@ -0,0 +1,3 @@
+USE prosody;
+
+ALTER TABLE sipwise_mam DROP KEY `with_idx`;

db_scripts/diff/15393.up

@@ -0,0 +1,3 @@
+USE prosody;
+
+ALTER TABLE sipwise_mam ADD KEY `with_idx` (`with`);