ext/ogg/gstoggdemux.c: Fix position for discont if we're close as well. Nitpicking, but saves a few milliseconds of e...

Original commit message from CVS:
* ext/ogg/gstoggdemux.c: (gst_ogg_demux_push):
Fix position for discont if we're close as well. Nitpicking, but
saves a few milliseconds of extra waiting or skipping.