lighttpd: upgrade 1.4.75 -> 1.4.76

Changelog:
==========
* [core] add default to builtin mimetype.assign
* [core] add MPTCP support
* [core] disable MPTCP support by default
* [mod_expire] omit caching hdrs for 204 No Content
* [mod_staticfile] noinline cold func
* [core] GNU/Hurd preadv2() RWF_NOWAIT ENOTSUP
* [core] special value for Linux POLLRDHUP on SPARC
* [mod_openssl] define asn1 time w/ OPENSSL_NO_OCSP
* [h2] VU#421644 HTTP/2 CONTINUATION Flood
* [build] packdist.sh git archive; replace make dist
* [core] gw_network_backend_write_error() cold func
* [core] reduce syscalls in some backend connect
* [core] defer TCP_FIN propagate if connect()ing
* [ci] workaround some packaging issues in NetBSD 10

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>