[pkg:nix] Change the download method.
[pkg:nix] Change the download method.

This will allow for better reuse of the cache when the URL is different
but the archive is the same.

ejgallego/coq,SkySkimmer/coq,gares/coq,maximedenes/coq,maximedenes/coq,ejgallego/coq,silene/coq,gares/coq,gares/coq,coq/coq,ejgallego/coq,maximedenes/coq,gares/coq,Zimmi48/coq,maximedenes/coq,coq/coq,ppedrot/coq,SkySkimmer/coq,gares/coq,ppedrot/coq,ppedrot/coq,coq/coq,JasonGross/coq,ppedrot/coq,silene/coq,SkySkimmer/coq,Matafou/coq,Zimmi48/coq,SkySkimmer/coq,Matafou/coq,Zimmi48/coq,JasonGross/coq,maximedenes/coq,silene/coq,JasonGross/coq,Matafou/coq,coq/coq,ejgallego/coq,ppedrot/coq,JasonGross/coq,Zimmi48/coq