core: Report slightly more accurate time seek range
core: Report slightly more accurate time seek range

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