Fix host header for connect proxy #2669

Job	Run time
build_versions (stable)	19s
build_versions (beta)	19s
Test	53s
build_versions (1.71.1)	19s
Test (charset)	52s
Test	53s
Test (cookies)	53s
cargo-deny (aarch64-apple-ios)	19s
Test (charset)	52s
Test (socks-proxy)	53s
Test (cookies)	52s
cargo-deny (aarch64-linux-android)	20s
Docs	1s
cargo-deny (i686-pc-windows-gnu)	1s
Test (socks-proxy)	51s
cargo-deny (i686-pc-windows-msvc)	1s
Test (gzip)	52s
cargo-deny (i686-unknown-linux-gnu)	1s
Test (gzip)	54s
cargo-deny (wasm32-unknown-unknown)	1s
Test (brotli)	51s
Test (brotli)	54s
cargo-deny (x86_64-apple-darwin)	1s
Test (json)	51s
Test (json)	54s
cargo-deny (x86_64-apple-ios)	1s
Lint	1s
Test (native-tls)	52s
Test (native-tls)	54s
cargo-deny (x86_64-pc-windows-gnu)	1s
cargo-deny (x86_64-pc-windows-msvc)	1s
Test (rustls-no-provider)	53s
cargo-deny (x86_64-unknown-linux-gnu)	1s
cargo-deny (x86_64-unknown-redox)	1s
	16m 42s

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