SVG gist 404 error test

test-svg-no-extension.txt

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg 
xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"
version="1.1" viewBox="0 0 300 300" preserveAspectRatio="none">
<defs>
<g id="horizontal-lines">
  <polyline vector-effect="non-scaling-stroke" points="0,100 300,100" />
  <polyline vector-effect="non-scaling-stroke" points="0,200 300,200" />
</g>
<g id="vertical-lines">
  <polyline vector-effect="non-scaling-stroke" points="100,0 100,300" />
  <polyline vector-effect="non-scaling-stroke" points="200,0 200,300" />
</g>
</defs>
<use xlink:href="#horizontal-lines" style="stroke: white; stroke-width: 4"/>
<use xlink:href="#horizontal-lines" style="stroke: black; stroke-width: 2"/>
<use xlink:href="#vertical-lines" style="stroke: white; stroke-width: 4"/>
<use xlink:href="#vertical-lines" style="stroke: black; stroke-width: 2"/>
</svg>

This 404s: https://gist.github.com/raw/4347712/c0b4b2e2eabe278a136f8c0405d7f75c70a8a3b0/test.svg

Clearly problem with SVG extension. This works fine:
https://gist.github.com/4347712#file-test-svg-no-extension