don't fail if we don't have a pad negotiation function
don't fail if we don't have a pad negotiation function

foolab/gst-droid,sledges/gst-droid,foolab/gst-droid,sledges/gst-droid,mlehtima/gst-droid,mlehtima/gst-droid,sledges/gst-droid,sailfishos/gst-droid