Fixes upstream issue #1350.
Notes:
Image uploads were incorrectly handled by Dino, as they were always
reported as completed even if they were not, maybe so as to show the
image preview from the start. Now, Dino shows the upload progress for
all file types, and the image is only shown when completed.
(cherry picked from commit 700708b7e10ce1110528a2b83b854fae3f6be95e)
595902355e