XmlAttributeDeserializer crashes if value == "". Put in a check for value == string.Empty instead of just checking if value == null.
Merge pull request #259 from Dharun/patch-1

XmlAttributeDeserializer crashes if value == ""
ConfigureProxy(http) was not being called in the ExecuteAsync().
Added ConfigureProxy(http) to the end of ConfigureHttp(request, http).
Removed call to ConfigureProxy(http) in Execute().