Issue with svg test expectation

[samnissen]

Previously we set the test it "handles cross-domain images and svgs" do to pending because the base64_canvas script can't handle that scenario. I've since totally reset my dev environment, and now the test fails (to fail). 50% of the time, it 'succeeds' with no errors, and 50% of the time it 'succeeds' but injected into the rspec readout is

mogrify: geometry does not contain image `/var/folders/f7/9kvchnq93gs02v8_hsp1y2bm0000gn/T/mini_magick20220126-79638-lf0lwd' @ warning/transform.c/CropImage/645.

A quick search of the error message suggests that the image might have a size of 0, suggesting browser updates might have broken the version of base64_canvas we're using? Or, perhaps my updated version of ImageMagick doesn't match our mini_magick or either of those has some other bug?