core: Fix a typo.
core: Fix a typo.

Fix a typo that prevented dc:creator from being included in DIDL output.

GNOME/rygel,luisbg/rygel,jku/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,Tarnyko/rygel,jku/rygel,Pelagicore/Media-Manager-Rygel-patched,Tarnyko/rygel