mathjax not rendering in HTML

[jcalvillo]

notebook/notebook/templates/notebook.html

Line 8 in 43df5af

<script type="text/javascript" src="{{mathjax_url}}?config={{mathjax_config}}&delayStartupUntil=configured" charset="utf-8"></script>

the URL from {{mathjax_url}} variable populates incorrectly.
It currently pupulates as:

<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS_HTML"></script>

The new, working mathjax URL from mathjax documentation is:

<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>

<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>

I've change the HTML manually in one of my exported notebooks and it's works correctly with the new URL.

[mgeier]

I guess currently version 2.7.x is used intentionally, but maybe it will be upgraded to v3 at some point, see #5758.