Fix 'confirmed' subscriptions becoming 'unconfirmed' on public form re-signup. Closes #1441.

queries.sql

@@ -178,6 +178,7 @@ INSERT INTO subscriber_lists (subscriber_id, list_id, status)
             WHEN $4='blocklisted' THEN 'unsubscribed'::subscription_status
             -- When subscriber is edited from the admin form, retain the status. Otherwise, a blocklisted
             -- subscriber when being re-enabled, their subscription statuses change.
+            WHEN subscriber_lists.status = 'confirmed' THEN 'confirmed'
             WHEN $9 = TRUE THEN subscriber_lists.status
             ELSE $8::subscription_status
         END