Be more picky about the trailing blank query string things we strip. props...

Be more picky about the trailing blank query string things we strip. props filosofo, fitztrev, stevish, azaozz, DD32 (go team!). fixes #8098. fixes #8180

git-svn-id: https://core.svn.wordpress.org/trunk@9642 1a063a9b-81f0-0310-95a4-ce76da25c4cd