Alessandro Decina authored Sep 05, 2016 and Tim-Philipp Müller committed Dec 09, 2017

Previously it was created in the init function and destroyed in ::stop, which
lead to segfaults when reusing the element.

Now the upload object is created in ::transform_caps if it is NULL, which is the
earliest we need it. The other vfuncs already bail out if the upload object is
NULL, which means that negotiation wasn't done.