Rejigger some whitespace in anticipation of a fix for #24364.

see #24364

git-svn-id: http://core.svn.wordpress.org/trunk@24551 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Combat Chrome's insanely aggressive user/pass autofilling ಠ_ಠ

Chrome now ignores `autocomplete="off"` in <input>, so this hack uses
a hidden, non-named, non-empty input, right before the password field.

see #24364. props azaozz, nacin, bobbingwide, aaroncampbell.

git-svn-id: http://core.svn.wordpress.org/trunk@24552 1a063a9b-81f0-0310-95a4-ce76da25c4cd