NullReferenceException in RaygunRequestMessage

I'm having a NullReferenceException with Raygun v1.0.3 inside the Mindscape.Raygun4Net.Messages.RaygunRequestMessage constructor (please see the attachment):
![raygun-nullref](https://f.cloud.github.com/assets/1866549/232108/2dbcfdb4-8725-11e2-98d0-2428bd182c40.png)

The fix is easy, add this on line 26: if (!string.IsNullOrEmpty(s)) { }