Varnish version 6.3 vcl test fails with custom http header starting with a number

[Dridi Boukelmoune]

> before submitting a bug a report in github wanted to check is someone is familiar with this issue ?

Can you tell us from which version you are upgrading to 6.3?

I know that at some point header names parsing changed so that they'd
have to be proper VCL symbols, leaving no room for otherwise valid
HTTP headers that don't happen to match VCL expectations. We have no
alternate syntax for "exotic" header names, I suggested req.http[7hello],
someone else suggested req.http."7hello" but nothing happened in this
direction. So your only solution today is to use vmod_header.

https://github.com/varnishcache/varnish-cache/issues/2573

Dridi