Wp-calypso: Import: Can't upload export file into IE11

[rachelmcr]

Steps to reproduce

1. In Windows IE 11, starting at URL: https://wpcalypso.wordpress.com/settings/import
2. Select "Start Import" and drag a file to the drag/drop box or click and select the file to import
   

   What I expected

The file will start to upload

What happened instead

There was no response in the UI, and the error Object doesn't support property or method 'find' appeared in the console:

The same issue occurred both when I tried to drag/drop the file, and when I clicked and selected the file to upload.

Browser / OS version

Windows 8.1, Internet Explorer 11

[BrookeDot]

Confirmed this is still an issue with IE 11. Tested on Windows 10 as well. Setting priority to high as this is a blocker for users of IE11.

cc:// @dmsnell do you agree this should be high priority?

[lancewillett]

Removing from high priority since import isn't being actively worked on right now.

[dmsnell]

All: Sorry for the neglect on this one. Please see #5736 for a fix - it's a relatively easy one I believe. Will merge after the reviews/tests.

[lancewillett]

Tested the fix, works nicely. 👍 🙇