Correct assertion for #14049 ticket

ec6eb38c64aadd6860c402cc0894c77b82b1a65d commit screwing up tests run in most browsers that do not support "order" CSS property. In order to do it "correctly" jQuery should also apply <code>-ms-flex-order</code> prefix to support it in IE10, but it would be too much of a special case.

I would be more comfortable to remove support for it entirely but otherwise test it like this - is the best way it could be done.

/cc @mzgol, @rwldrn, @jasonmerino