Fix server crashing when receiving POST multipart-formdata request with a body that contains a value of "PUT", "POST", "GET" etc. #13

[PhilippMDoerner]

I recently discovered a bug in httpx while using prologue. As httpx is a fork of httpbeast, it could be that httpbeast shared similar issues. Here a link to the issue in httpx with a minimal example in prologue:

https://github.com/ringabout/httpx/issues/13