Theme Customizer: Plupload does not support objects in its multipart_params...

Theme Customizer: Plupload does not support objects in its multipart_params setting (which causes exceptions in Firefox). Use multidimensional keys to circumnavigate this issue. see #19910.

git-svn-id: https://core.svn.wordpress.org/trunk@20253 1a063a9b-81f0-0310-95a4-ce76da25c4cd