Do not invent HttpStatus codes when one was not recieved

[John Erickson]

This section of code has bitten us multiple times. If a HttpStatus code is not received over the wire, then the SDK should not pretend one was.

When it fabricates a status code it makes debugging very difficult.

azure-storage-net/Lib/Common/StorageException.cs

Lines 305 to 325 in bbb7da6

 else if (ex is TimeoutException) 
 { 
     reqResult.HttpStatusMessage = null; 
     reqResult.HttpStatusCode = (int)HttpStatusCode.RequestTimeout; 
     reqResult.ExtendedErrorInformation = null; 
     return new StorageException(reqResult, ex.Message, ex); 
 } 
 else if (ex is ArgumentException) 
 { 
     reqResult.HttpStatusMessage = null; 
     reqResult.HttpStatusCode = (int)HttpStatusCode.Unused; 
     reqResult.ExtendedErrorInformation = null; 
     return new StorageException(reqResult, ex.Message, ex) { IsRetryable = false }; 
 } 
 else if (ex is OperationCanceledException) 
 { 
     reqResult.HttpStatusMessage = null; 
     reqResult.HttpStatusCode = 306; // unused 
     reqResult.ExtendedErrorInformation = null; 
     return new StorageException(reqResult, ex.Message, ex); 
 }