title: TwitterService.GetRequestToken throws exception "Value cannot be null. Parameter name: query"
body: <p>An week ago I faced a problem with getting request token from TweetSharp library, every time it throws null exception. Previously it works, credentials are valid. The same problem with test from <a href="https://github.com/shugonta/tweetsharp" rel="nofollow noreferrer">https://github.com/shugonta/tweetsharp</a>
  Looks like again some problem with TweetSharp proxy.</p>
  
  <pre><code>var service = new TwitterService(_consumerKey, _consumerSecret);
  var requestToken = service.GetRequestToken();
  
  System.ArgumentNullException : Value cannot be null.
  Parameter name: query
     at System.Compat.Web.HttpUtility.ParseQueryString(String query, Encoding encoding) in D:\My Dropbox\_7_Source_Code\_1_Projects\hammock-codeplex\src\net40\Hammock.ClientProfile\Mono\HttpUtility.cs:line 1222
     at TweetSharp.TwitterService.GetRequestToken(String callback) in C:\Users\Boker\Desktop\tweetsharp-master\src\net40\TweetSharp.Next\Service\TwitterService.OAuth.cs:line 171
     at TweetSharp.TwitterService.GetRequestToken() in C:\Users\Boker\Desktop\tweetsharp-master\src\net40\TweetSharp.Next\Service\TwitterService.OAuth.cs:line 184
     at TweetSharp.Tests.Service.TwitterServiceTests.Can_exchange_for_access_token() in C:\Users\Boker\Desktop\tweetsharp-master\src\net40\TweetSharp.Next.Tests\Service\TwitterServiceTests.OAuth.cs:line 26
  </code></pre>