Update Mathjax CND url according to https://www.mathjax.org/cdn-shutting-down/.
Update Mathjax CND url according to https://www.mathjax.org/cdn-shutting-down/.

tomzx/blog.tomrochette.com,tomzx/blog.tomrochette.com,tomzx/blog.tomrochette.com,tomzx/blog.tomrochette.com