🐛 [Bug]: Fiber masks errors raised in fasthttp

[WoLfulus]

Bug Description

Fiber will mask any internal error in fasthttp with a BadRequest response. This was a pain to debug, even with stack traces the original error won't popup. The only I could find the error was to modify fiber to drop the err = ErrBadRequest overwrite in server.go to let the original fasthttp error to land on my ErrorHandler

Would be nice to at least wrap the original error in order to get the reason why something is failing.

How to Reproduce

Steps to reproduce the behavior:

Build a file uploader without streaming, build it inside a scratch container, and try to read the multipart file.

The error will be masked with a Bad Request (in this case it was a missing /tmp folder inside the scratch containerin which fasthttp couldn't write/read from)

Expected Behavior

Be able to view original error reasons when they happen

Fiber Version

v2.40.1

Code Snippet (optional)

No response

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my problem prior to opening this one.
• I understand that improperly formatted bug reports may be closed without explanation.

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