Fix the upgrade migration of custom profile fields in #2545

The upgrade_2-1_postgresql.sql changes are untested, but do match the changes to upgrade_2-1_mysql.sql that are tested and confirmed to fix the upgrade issues in #2545.

Signed-off-by: Noteworthy Software, Inc <online@noteworthysoftware.com>
I didn't even notice that somehow. That should work for this at least. We'll still need to adjust anything else that checks for version < 2.1 in this file.