Change isEqualToString to hasPrefix.


I replace my library with AFOAuth1Client.
During migration, I have a "Invalid token" error.

I searched whole day and finally figure out "Authorization" header does not include oauth_verifier, oauth_callback.

In requestWithMethod:path:paramters: method,
authorizationParameters will be nil if Content-Type is not EQUAL "application/x-www-form-urlencoded".

Because AFHttpClient set Content-Type "application/x-www-form-urlencoded; charset=utf-8",  authorizationParameters always be nil, and header does not verifier and callback.

So I changed isEqualToString -> hasPrefix, in requestWithMethod:path:parameters and multipartFormRequestWithMethod:path:parameters:constructingBodyWithBlock methods.