ContentType.FormData no longer sets the correct boundary

[Styn]

This PR: 29d89ec
breaks the boundary setting for FormData.

Right now the header will look like this: Content-Type: multipart/form-data instead of something like Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryUAzmDsnaGSk1qaI3

[js2me]

Hello @Styn !
Thanks for this issue, can you fix that problem and create PR ?

[js2me]

Or if not, don't worry I'll fix that but I need a bit more time

[Styn]

I'll have a PR up soon

[js2me]

@Styn fixed in 5.1.5, thank you!