Fixed CRHTTPConnection query URL parsing

[itsjunetime]

In CRHTTPConnection.m, the query URL that is being constructed from the HTTP data isn't being percent encoded. This means that if it includes some special characters such as backticks or carets, the NSURL that is constructed will be nil, and the server won't be able to correctly handle the request.

This PR simply adds percent encoding so that it correctly sets the URL, and services the request as expected.