- use parallel build

- Update to version 2.2.4+git0.de456726d:
* [RELEASE] Released version 2.2.4
* REGTEST: make map_regm_with_backref require 1.7
* REGTEST: make abns_socket.vtc require 1.8
* REGTEST: make agent-check.vtc require 1.8
* REGTEST: fix host part in balance-uri-path-only.vtc
* BUG/MINOR: ssl/crt-list: exit on warning out of crtlist_parse_line()
* DOC: agent-check: fix typo in "fail" word expected reply
* REGTESTS: use "command" instead of "which" for better POSIX compatibility
* BUILD: trace: include tools.h
* BUG/MEDIUM: listeners: do not pause foreign listeners
* REGTESTS: add a few load balancing tests
* MINOR: backend: add a new "path-only" option to "balance uri"
* MINOR: backend: make the "whole" option of balance uri take only one bit
* MINOR: h2/trace: also display the remaining frame length in traces
* BUG/MINOR: Fix memory leaks cfg_parse_peers
* BUG/MEDIUM: h2: report frame bits only for handled types
* BUG/MINOR: config: Fix memory leak on config parse listen
* BUG/MINOR: http-fetch: Don't set the sample type during the htx prefetch
* BUG/MINOR: h2/trace: do not display "stream error" after a frame ACK
* BUG/MINOR: ssl/crt-list: crt-list could end without a \n
* BUG/MEDIUM: ssl: Don't call ssl_sock_io_cb() directly.
* BUG/MINOR: server: report correct error message for invalid port on "socks4"
* BUG/MINOR: ssl: verifyhost is case sensitive
* BUG/MINOR: Fix type passed of sizeof() for calloc()
* BUG/MEDIUM: pattern: Renew the pattern expression revision when it is pruned
* BUILD: threads: better workaround for late loading of libgcc_s