Get rid of CString alloc in OwnedHeader::insert #665

Job	Run time
check-minimal-versions	59s
check-minimal-versions	59s
check-minimal-versions	59s
check-minimal-versions	59s
lint	2m 18s
lint	2m 18s
lint	2m 18s
lint	2m 18s
test (7.7.0, 3.7)	2m 25s
test (7.7.0, 3.7)	3m 11s
test (7.7.0, 3.7)	3m 11s
test (7.7.0, 3.7)	3m 11s
check (macos-11.0)	1s
check (macos-11.0)	1s
check (macos-11.0)	1s
check (macos-11.0)	1s
test (7.5.1, 3.6)	2m 38s
test (7.5.1, 3.6)	2m 42s
test (7.5.1, 3.6)	2m 30s
test (7.5.1, 3.6)	2m 32s
check (windows-2019, cmake-build,libz-static,curl-static, cmake-build,libz-static,curl-static)	5m 28s
check (windows-2019, cmake-build,libz-static,curl-static, cmake-build,libz-static,curl-static)	5m 28s
check (windows-2019, cmake-build,libz-static,curl-static, cmake-build,libz-static,curl-static)	5m 28s
check (windows-2019, cmake-build,libz-static,curl-static, cmake-build,libz-static,curl-static)	5m 28s
test (7.5.1, 3.5)	2m 23s
test (7.5.1, 3.5)	2m 41s
test (7.5.1, 3.5)	2m 24s
test (7.5.1, 3.5)	2m 20s
check (ubuntu-20.04, tracing)	2m 0s
check (ubuntu-20.04, tracing)	2m 0s
check (ubuntu-20.04, tracing)	2m 0s
check (ubuntu-20.04, tracing)	2m 0s
check (ubuntu-20.04, cmake-build,ssl-vendored,gssapi-vendored,libz-static,curl-static,zstd, cmake...	3m 25s
check (ubuntu-20.04, cmake-build,ssl-vendored,gssapi-vendored,libz-static,curl-static,zstd, cmake...	3m 25s
check (ubuntu-20.04, cmake-build,ssl-vendored,gssapi-vendored,libz-static,curl-static,zstd, cmake...	3m 25s
check (ubuntu-20.04, cmake-build,ssl-vendored,gssapi-vendored,libz-static,curl-static,zstd, cmake...	3m 25s
	1h 28m 52s

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