snf_django: Fix unicode error in proxy requests
Pithos and Cyclades services need to proxy Astakos API calls for enabling the web clients to access them. Proxy requests containing non ASCII characters used to fail. The reason was that the proxy tried to make a request using the original request path. However Django forces the request path to be unicode. Therefore, the httplib used to fail because it tried to concatenate unicode and bytestrings. This fix changes the original implementation and from now on it sends the requested URL encoded in UTF-8.