Comment 1 for bug 1879993

Working branch user/jeffdavis/lp1879993-default-hold-notify-upstream uses the reg_default value for the opac.hold_notify user setting on the patron registration page:

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/jeffdavis/lp1879993-default-hold-notify-upstream

The reg_default will also be used when editing an existing patron who has no opac.hold_notify user setting. In either case, you can use an empty string ("") as the setting value in order to keep all boxes unchecked. If there is no user setting and no default value, both phone and email will be checked, which is consistent with current behavior.

Test plan:

[1] In config.usr_setting_type, set the reg_default for opac.hold_notify to "email".
[2] Register a new patron. The default value is applied: under Hold Notices, phone is unchecked and email is checked.
[3] Edit an existing patron with no opac.hold_notify setting. The default value is applied: under Hold Notices, phone is unchecked and email is checked.
[4] Edit an existing user who *does* have an opac.hold_notify setting. The boxes will be checked in accordance with the setting.