Bug 37324: Self registration complete login form won't login user

Bug 37324: Self registration complete login form won't login user

This patch fixes the self registration complete login form which appears after a complete self registration process.

To test:
a) open http://localhost:8081/cgi-bin/koha/admin/preferences.pl?op=search&searchfield=PatronSelfRegistrationDefaultCategory
b) set PatronSelfRegistration to allow
c) set PatronSelfRegistrationDefaultCategory to Self registration
d) logout or open a private tab
e) http://localhost:8080/cgi-bin/koha/opac-memberentry.pl and enter required fields
f) Registration complete! appears with a prefilled login form. Click Log in.
g) Check you are not logged in

apply patch and redo steps e-f and check that login worked.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>