Fix description of 'email as login' security setting.

It said existing users could go to the personalize information page and save
it to start using their email as login, but that no longer works and
is too hard to fix.  We now only recommend using the
migrate-to-emaillogin page as manager.
Fixes #11283
No https in CHANGES.txt
history
i18n "Test e-mail" subject & message
Merge pull request #12 from jianaijun/master

 i18n "Test e-mail" subject & message
Preparing release 2.3.3
Back to development: 2.3.4
Call searchUsers with the 'name' argument instead of 'login'.

'name' is the officially supported way according to the PAS interface.
emaillogin.pt: change 'li' to 'ol'.

Apparently 'li' is not shown under each other here, but 'ol' is.
Removed double space in use_email_as_login_description.
Avoid extra acquisition step: self.context is already site_properties.
Preparing release 2.3.4
Back to development: 2.3.5