WebAlert: CSS cleanup

* Improves compatibility with Bootstrap 3.  (closes #1644)

Co-authored-by: Eirini Psallida <eirini.psallida@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
login: fix redirection to secure page

* Fixes an issue when endpoint needed view arguments to generate
  `secure_url` for comparison with `request.base_url`.  (closes #2052)

Signed-off-by: Eirini Psallida <eirini.psallida@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>