Preserve the 'Remember Me' flag throughout the login process.

Previously it got lost during the 2FA token prompt redirection, so users requesting to have their cookie expiration extended would not get it.


git-svn-id: https://plugins.svn.wordpress.org/google-authenticator-per-user-prompt/trunk@912462 b8457f37-d9ea-0310-8a92-e5e31aec5664