Backport !1781 “gs-download-utils: Cover case where `local_error` is set, but message status is 200” to gnome-44
requested to merge pwithnall/gnome-software:backport-1781-download-error-handling-gnome-44 into gnome-44
There can happen that the libsoup call fails, and sets the local_error, but
the message's status is left as 200, which is success. In such case
the g_assert() on input_stream being non-NULL triggers and aborts
the application.
Closes #2313 (closed)
Trivial backport of !1781 (merged) to gnome-44.