Don't set post_type QV in _post_format_request() when we're in the admin....

Don't set post_type QV in _post_format_request() when we're in the admin. props ethitter. fixes #18475.

git-svn-id: https://core.svn.wordpress.org/trunk@19193 1a063a9b-81f0-0310-95a4-ce76da25c4cd