Allows emacs version to parse json

Fixes issue: https://github.com/igrigorik/vimgolf/issues/132
I was referencing the weird error I got when I did not redefine url-http-end-of-headers: 
```Symbol's function definition is void: url-http-end-of-headers```

I can't manage to reproduce it now.

The line ```(declare (special url-http-end-of-headers))``` was unnecessary, as you mentioned earlier.