Drop the metamta_mailinglist table

Summary: We haven't seen any issues here, remove the table and schema spec.

Test Plan: Not yet tested.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D14067

resources/sql/autopatches/20150906.mailinglist.sql

@@ -0,0 +1 @@
+DROP TABLE {$NAMESPACE}_metamta.metamta_mailinglist;