Add render_value to various PasswordInput fields.
For password inputs that are part of settings (LDAP auth, mail host, and

repository), the password wasn't pre-populated into the form, which meant that

if you changed said settings, you'd need to re-enter the password. This is

highly annoying. I've added render_value=True to the affected PasswordInput

ctors.

Checked that saving a password was "sticky".