Pass topics to mailserver cursor

The topics field was not passed to the mailserver, which meant that
queries were still using the old bloom filter.
Hopefully this is the last place where we need to pass this.

VERSION

@@ -1 +1 @@
-0.68.6
+0.68.7

mailserver/mailserver.go

@@ -958,6 +958,7 @@ func (s *mailServer) createIterator(req MessagesRequestPayload) (Iterator, error
 		start:  kl.Bytes(),
 		end:    ku.Bytes(),
 		cursor: req.Cursor,
+		topics: req.Topics,
 		bloom:  req.Bloom,
 		limit:  req.Limit,
 	}