Fix org-element-cache issue with ansi colors

[akirakyle]

I was getting really annoyed with all the org-element-cache warnings using ob-jupyter with julia which are described in #486 so I tried to figure out what was causing them. I'm not sure if this is the right way to fix it, or if it may also be caused by other things in emcas-jupyter, but so far I haven't been seeing the issue with this patch for my workflows.

[MasonProtter]

I tried this branch to see if if fixed #522, and while I no longer get the warnings, the ansi colours are no longer displayed:

vs before:

[akirakyle]

Can you try revert-buffer to see if the ansi escape sequences get rendered? I've encountered this here but haven't had time to debug it.

[MasonProtter]

Oh interesting, yeah a revert-buffer did work!