configure: require core/base 0.10.31
configure: require core/base 0.10.31

Needed at least for gst_plugin_feature_rank_compare_func().

barisdemiray/gst-rtsp-server,surround-io/gst-rtsp-server,barisdemiray/gst-rtsp-server,thaytan/gst-rtsp-server,thaytan/gst-rtsp-server,surround-io/gst-rtsp-server,Lachann/gst-rtsp-server,barisdemiray/gst-rtsp-server,thaytan/gst-rtsp-server,Lachann/gst-rtsp-server,Lachann/gst-rtsp-server,surround-io/gst-rtsp-server,hsteinhaus/gst-rtsp-server,hsteinhaus/gst-rtsp-server,hsteinhaus/gst-rtsp-server