bug fix: profile fields can now be edited if their type is not set.

This includes child profile field that could not be edited for a while.
Also added a feature spec for that.

Trello: https://trello.com/c/kmaRSYY6/613-fix-child-felder-werden-nicht-gespeichert.

There is no corresponding uservoice ticket. Apparently, users have not found
this issue.

This commit resolves the issue.