Guys, sorry for the late answer. For some reason I don't receive notifications from this thread after a while.

If there's a problem resolving dependencies, try pkcon refresh in terminal. It will update available packages, and gst-plugins-good is there again. I think I'll change RPM spec to gstreamer1.0-plugins-good for the next Sailfish version, as it should be Qt 5.6-based and the app needs to be repackaged anyway.