Revert "collectpads: Assume PTS is equal DTS if PTS is missing"
Revert "collectpads: Assume PTS is equal DTS if PTS is missing"

This reverts commit 9b0d42ceecb3198399d7e05e3d5f080a7ca27ca9.

https://bugzilla.gnome.org/show_bug.cgi?id=762207

StreamUtils/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer