Fix migration 015 downgrade with sqlite.

This adds a list() call around the select sqlalchemy to pull
the list of locations that start with swift. The list() call
forces the select query to finish, before we try to update the
database.

Change-Id: I63f2e184a49e8bbd7115dd59d644506ea4069558
Remove unnecessary logging from migration 019

Migration 019 included debug logging for every sqlalchemy call
that was run. This commit removes all of the logging and makes it
consistent with the other migrations.

Change-Id: I914f4f4458eacbb3bcabac092bbe166ce9069a5f
Merge "Fix migration 015 downgrade with sqlite."
Merge "Remove unnecessary logging from migration 019"