[#283] Server: allow overwriting "Server" response header (@skazhy)
[#283] Server: allow overwriting "Server" response header (@skazhy)

http-kit/http-kit,ptaoussanis/http-kit,http-kit/http-kit,http-kit/http-kit,ptaoussanis/http-kit,ptaoussanis/http-kit,ptaoussanis/http-kit,http-kit/http-kit,http-kit/http-kit,http-kit/http-kit,ptaoussanis/http-kit,ptaoussanis/http-kit