Bug 27450: Remove password from the mandatory fields when editing details

Bug 27450: Remove password from the mandatory fields when editing details

When a patron edit their personal details at the OPAC, the password must
be removed from the mandatory fields

Test plan:
0 - Don't apply the patch
1 - Set PatronSelfRegistrationBorrowerMandatoryField to require password
2 - Create or sign in as a patron on the opac
3 - Click 'Your personal details'
4 - Attempt to edit
5 - Save changes
=> They are rejected because not all required fields are populated
6 - Apply the patch
7 - Repeat 3 to 5
=> details are saved successfully
8 - Test the self registration feature and confirm that the password is
required

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>