in pull requests' discussion pages (like https://github.com/kidd/org-protocol-github-lines/pull/1 ), there's also a span with class mini-icon-text-file, and the script fails when trying to fetch the fileLink.  I guess with a 

`if(!fileLink) {return;}`

it'd be solved. or maybe enabling the script only on github.com/*/*  (don't know if the * wildcard will do 'the proper thing').  
Could you fix that with the solution that you find more appropiate?

Thx!