Upload API - Boundary quotes when using Microsoft Web API

If you ever used Microsoft Web API client ( System.Net.Http.HttpClient), you may have found that using our Upload API fails. This is because our backend expects the multipart content boundary without any quotes, like below:-

What FileSpin backend expects from the Uploading client

Content-Type: multipart/form-data; boundary=123456789

What some Microsoft Web API clients send

Content-Type: multipart/form-data; boundary="123456789"

Notice the quotes around the boundary value "123456789". 

In order to use the Upload API with Microsoft Web API that formats payload like above, strip the double quotes from the boundary value.