tracker: Correct icon path
tracker: Correct icon path

Load icon from tracker's icon directory rather than Rygel's.

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