mathgl: Fix sha256 of Linux bottle
mathgl: Fix sha256 of Linux bottle

Closes #6154.

Signed-off-by: Michka Popoff <7b0496f66f66ee22a38826c310c38b415671b832@gmail.com>

pditommaso/homebrew-science,heuermh/homebrew-science,andrewjpage/homebrew-science