jquery.badge: Swap non-breaking space character for regular space

Follows-up d453f81f4e. PHP's native json_encode requires input
being a UTF-8 string. For some reason MediaWiki, Git or OS X is
not reading jquery.badge.css as UTF-8 for me.

https://bugs.php.net/bug.php?id=51947

Due to json_encode rejecting the entire value and returning null
instead, the jquery.badge stylesheet was absent. load.php:

 mw.loader.implement("jquery.badge",function, {"css":[null]} );

Change-Id: I84d2017a976249f55bdb269d2b9762db941292fe