autogen.sh: advice about installing autoconf if autoreconf not found
autogen.sh: advice about installing autoconf if autoreconf not found

freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp,GStreamer/gstreamer-sharp,GStreamer/gstreamer-sharp,GStreamer/gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp