configure.ac: 0.10.19.4 pre-release
configure.ac: 0.10.19.4 pre-release

Skip .3 to align number with the other pre-releases.

alessandrod/gst-python,pexip/gst-python,pexip/gst-python,lubosz/gst-python,freedesktop-unofficial-mirror/gstreamer-sdk__gst-python,freedesktop-unofficial-mirror/gstreamer-sdk__gst-python,pexip/gst-python,alessandrod/gst-python,freedesktop-unofficial-mirror/gstreamer-sdk__gst-python,GStreamer/gst-python,lubosz/gst-python,freedesktop-unofficial-mirror/gstreamer-sdk__gst-python,alessandrod/gst-python,lubosz/gst-python,freedesktop-unofficial-mirror/gstreamer__gst-python,freedesktop-unofficial-mirror/gstreamer__gst-python,freedesktop-unofficial-mirror/gstreamer__gst-python,GStreamer/gst-python,GStreamer/gst-python