deps: update http-parser to 2.6.0

significant updates:

* [[`777ba4eded`](https://github.com/nodejs/node/commit/777ba4eded)] - **src**: introduce `http_parser_url_init` (Fedor Indutny) [nodejs/http-parser#225](https://github.com/nodejs/http-parser/pull/225)
* [[`e557b62744`](https://github.com/nodejs/node/commit/e557b62744)] - **src**: support LINK/UNLINK (RFC 2068, draft-snell-link-method) (Olivier Mengué) [nodejs/http-parser#267](https://github.com/nodejs/http-parser/pull/267)
* [[`eb5e9928b4`](https://github.com/nodejs/node/commit/eb5e9928b4)] - **src**: support ACL (WebDAV, RFC3744, Section 8.1). (Ivan Enderlin) [joyent/http-parser#260](https://github.com/joyent/http-parser/pull/260)
* [[`8b1d652322`](https://github.com/nodejs/node/commit/8b1d652322)] - **src**: support BIND/REBIND/UNBIND (WebDAV, RFC5842) (Ivan Enderlin) [joyent/http-parser#242](https://github.com/joyent/http-parser/pull/242)
* [[`7d75dd7325`](https://github.com/nodejs/node/commit/7d75dd7325)] - **src**: support IPv6 Zone ID as per RFC 6874 (Tatsuhiro Tsujikawa) [joyent/http-parser#253](https://github.com/joyent/http-parser/pull/253)

PR-URL: https://github.com/nodejs/node/pull/3569


Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>