autogen.sh: don't run ./configure if autoreconf failed
autogen.sh: don't run ./configure if autoreconf failed

The following line could be seen in the middle of the log:
autoreconf: automake failed with exit status: 1

Clearly the configuration phase should not continue from there.

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