core: Use replace_literal in MediaArtStore
core: Use replace_literal in MediaArtStore

The regex doesn't use back references so we can use the slightly more
efficient version

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