server: Fix ambiguity of default "this"
server: Fix ambiguity of default "this"

Fixes a warning in MediaExport when removing a file.

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