Variables passed by reference do not need to be set first.

props kovshenin.
see #24222.



git-svn-id: https://core.svn.wordpress.org/trunk@24129 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Better logic for preg_match() calls in ms-functions.php. fixes #24222.



git-svn-id: https://core.svn.wordpress.org/trunk@24130 1a063a9b-81f0-0310-95a4-ce76da25c4cd