x264enc: increase bitrate limit from 100Mbps to 2Gbps
x264enc: increase bitrate limit from 100Mbps to 2Gbps

Don't artificially limit the bitrate, x264enc allows much
higher bitrates, and for intra-only 4k AVC they are needed.
x264 clips to 2Gbps internally, so use that as limit for now.

https://bugzilla.gnome.org/show_bug.cgi?id=758620

Kurento/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,Kurento/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,GStreamer/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,GrokImageCompression/gst-plugins-ugly,StreamUtils/gst-plugins-ugly,GStreamer/gst-plugins-ugly,Kurento/gst-plugins-ugly,GStreamer/gst-plugins-ugly