splitmuxsink: Don't accumulate more than 2 GOPs
splitmuxsink: Don't accumulate more than 2 GOPs

Don't allow large amounts of data to queue up - we only need
the GOP we're writing, and the GOP we're accumulating.

kittee/gst-plugins-good,Kurento/gst-plugins-good,rawoul/gst-plugins-good,sebras/gst-plugins-good,StreamUtils/gst-plugins-good,froggatt/gst-plugins-good-m,kittee/gst-plugins-good,GStreamer/gst-plugins-good,sebras/gst-plugins-good,GrokImageCompression/gst-plugins-good,hizukiayaka/gst-plugins-good,StreamUtils/gst-plugins-good,shelsonjava/gst-plugins-good,Kurento/gst-plugins-good,froggatt/gst-plugins-good-m,shelsonjava/gst-plugins-good,GStreamer/gst-plugins-good,ikonst/gst-plugins-good,froggatt/gst-plugins-good-m,GrokImageCompression/gst-plugins-good,GStreamer/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,pexip/gst-plugins-good,hizukiayaka/gst-plugins-good,chamois94/gst-plugins-good,rawoul/gst-plugins-good,chamois94/gst-plugins-good,shelsonjava/gst-plugins-good,pexip/gst-plugins-good,shelsonjava/gst-plugins-good,pexip/gst-plugins-good,stfl/gst-plugins-good,stfl/gst-plugins-good,GrokImageCompression/gst-plugins-good,vatavuserban/gst-plugins-good,Kurento/gst-plugins-good,ikonst/gst-plugins-good,vatavuserban/gst-plugins-good,StreamUtils/gst-plugins-good,vatavuserban/gst-plugins-good,pexip/gst-plugins-good,chamois94/gst-plugins-good,sebras/gst-plugins-good,StreamUtils/gst-plugins-good,hizukiayaka/gst-plugins-good,sebras/gst-plugins-good,kittee/gst-plugins-good,kittee/gst-plugins-good,hizukiayaka/gst-plugins-good,rawoul/gst-plugins-good,ikonst/gst-plugins-good,chamois94/gst-plugins-good,Kurento/gst-plugins-good,rawoul/gst-plugins-good,Kurento/gst-plugins-good,ikonst/gst-plugins-good,froggatt/gst-plugins-good-m,vatavuserban/gst-plugins-good,GrokImageCompression/gst-plugins-good,stfl/gst-plugins-good,stfl/gst-plugins-good