Allow to set email address to private independent of sharing settings

Steps to reproduce

1. Disable "Allow users to publish their data to a global and public address book" under /Settings/Share
2. Goto "Personal info" and look for the option to handle email address as "private" or share with local "contacts"
3. Enable "Allow users to publish their data to a global and public address book" under /Settings/Share
4. Goto "Personal info" and look again

Expected behaviour

The option for Private/Contacts should appear always

Actual behaviour

The option disappears while the "Public"-option disappears.
The problem is that users can see the email address of other users in the contacts menu.

Video for lazy guys:
privacysettings.zip
Reference:
help.nextcloud.com

Server configuration

Nextcloud version: 13.0.2

Updated from an older Nextcloud/ownCloud or fresh install: demo.nextcloud.com=N/A; own Nextcloud=updated

Where did you install Nextcloud from: tar

Signing status:

Login as admin user into your Nextcloud and access 
http://example.com/index.php/settings/integrity/failed 
paste the results here.

Are you using encryption: no

Are you using an external user-backend, if yes which one: no

Client configuration

Browser: FF 60.0.1

Operating system: Win10.1709

Logs

Web server error log

Reproduce the behavior from /Settings/Share and the Personal info page with public address-book sharing disabled and enabled. Trace how the Private/Contacts option is shown in those settings screens, then verify that it remains available when the Public option is disabled and that other users' email addresses are no longer exposed through Contacts.