Bug 36983: Fix incorrect required class

Bug 36983: Fix incorrect required class

This patch fixes an error on the B_address2 field which sets it to be
required incorrectly

Test plan:
1) In PatronSelfRegistrationBorrowerMandatoryField, set B_address to be
   required.
2) In the OPAC, navigate to the self registration form.
3) In the Alternate address section, fill in the Address field that you
   have just set to be required. Ensure that you leave the Address 2
   field blank.
4) Fill in all other required fields and submit the form, it should show
   you that the Address 2 field is required, even though it shouldn't be
5) Apply patch
6) Refresh the page and repeat steps 1-5, it should allow youto submit
   the form

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>