Bug 19235: Password entry visible in OPAC Self-registration

Bug 19235: Password entry visible in OPAC Self-registration

The HTML code was "text" instead of "password".

TEST PLAN
----------
1) 'Allow' PatronSelfRegistration system preference
2) Define the PatronSelfRegistrationDefaultCategory system preference (e.g. PT)
3) Open OPAC
4) Click 'Register here' on the right.  (/cgi-bin/koha/opac-memberentry.pl)
5) Scroll to bottom
6) enter some passwords
   -- visible
7) apply this patch
8) refresh page
9) repeat 5-6 as needed
   -- passwords should not be visible while entering
10) run koha qa test tools

Signed-off-by: Lee Jamison <ldjamison@marywood.edu>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>