DefaultAcsClient's DoAction<T> overload methods have BUG

[VAllens]

Error Code

FormatType? requestFormatType = request.AcceptFormat;
if (null != requestFormatType)
{
    format = requestFormatType;
}

Right Code

if (null == format)
{
    format = request.AcceptFormat;
}

I see that this method has Nullable type parameter format. I thought you were going to judge if the parameter format was empty, otherwise the code if (null != requestFormatType) would be meaningless. Because it's always true.

[conan425]

We will consider your suggestion，Thank you very much!