Update media_mediamosa.stream.wrapper.class.inc

The oneliner was generating warnings:

Strict warning: Only variables should be passed by reference in MediaMosaStreamWrapper::mediamosa_parse_url_from_fid() (regel 80 van C:\wamp\www\ingebeeld\www\sites\all\modules\contrib\mediamosa-ck\modules\media_mediamosa\media_mediamosa.stream.wrapper.class.inc).