Fix resource proxy encoding errors

Some resources cannot be proxied because of encoding issues. For example http://www.berlin.de/ba-lichtenberg/buergerservice/familie/tagespflege/index.php/index/all.json?q=. 

The error in Firefox: `Content Encoding Error`
In Chrome: `Error 330 (net::ERR_CONTENT_DECODING_FAILED): Unknown error.`
In curl: `url: (56) Problem (2) in the Chunked-Encoded data`