Prevent "Add" button in Tags meta box from wrapping to a new line in ru_RU.

fixes #29265. see #26510.
Built from https://develop.svn.wordpress.org/trunk@29539


git-svn-id: http://core.svn.wordpress.org/trunk@29315 1a063a9b-81f0-0310-95a4-ce76da25c4cd