Comment 0 for bug 1838771

Currently CONNECT requests use the name of the proxy as Host value, instead of
the origin server's name.

According to RFC 2616 "The Host field value MUST represent the naming authority
of the origin server or gateway given by the original URL."

The current implementation causes problems with some proxy vendors. This
commit[0] fixes this.

# salsa
$ git describe --contains 86d4d98060f36c7e71c34af20a1193a75496ef72
1.9.0~8

# rmadison apt
=> apt | 1.6.11 | bionic-updates | source, amd64, arm64, armhf, i386, ppc64el, s390x
=> apt | 1.8.1 | disco-updates | source, amd64, arm64, armhf, i386, ppc64el, s390x
apt | 1.9.1 | eoan | source, amd64, arm64, armhf, i386, ppc64el, s390x

[0] - https://salsa.debian.org/apt-team/apt/commit/86d4d98060f36c7e71c34af20a1193a75496ef72#54d3193c5d10a0032c80c3a6d3f069507265547f