[RELEASE] Released version 2.3-dev3

Released version 2.3-dev3 with the following main changes :
    - SCRIPTS: git-show-backports: make -m most only show the left branch
    - SCRIPTS: git-show-backports: emit the shell command to backport a commit
    - BUILD: Makefile: require SSL_LIB, SSL_INC to be explicitly set
    - CI: travis-ci: specify SLZ_LIB, SLZ_INC for travis builds
    - BUG/MEDIUM: mux-h1: Refresh H1 connection timeout after a synchronous send
    - CLEANUP: dns: typo in reported error message
    - BUG/MAJOR: dns: disabled servers through SRV records never recover
    - BUG/MINOR: spoa-server: fix size_t format printing
    - DOC: spoa-server: fix false friends `actually`
    - BUG/MINOR: ssl: fix memory leak at OCSP loading
    - BUG/MEDIUM: ssl: memory leak of ocsp data at SSL_CTX_free()
    - BUG/MEDIUM: map/lua: Return an error if a map is loaded during runtime
    - MINOR: arg: Add an argument type to keep a reference on opaque data
    - BUG/MINOR: converters: Store the sink in an arg pointer for debug() converter
    - BUG/MINOR: lua: Duplicate map name to load it when a new Map object is created
    - BUG/MINOR: arg: Fix leaks during arguments validation for fetches/converters
    - BUG/MINOR: lua: Check argument type to convert it to IPv4/IPv6 arg validation
    - BUG/MINOR: lua: Check argument type to convert it to IP mask in arg validation
    - MINOR: hlua: Don't needlessly copy lua strings in trash during args validation
    - BUG/MINOR: lua: Duplicate lua strings in sample fetches/converters arg array
    - MEDIUM: lua: Don't filter exported fetches and converters
    - MINOR: lua: Add support for userlist as fetches and converters arguments
    - MINOR: lua: Add support for regex as fetches and converters arguments
    - MINOR: arg: Use chunk_destroy() to release string arguments
    - BUG/MINOR: snapshots: leak of snapshots on deinit()
    - CLEANUP: ssl: ssl_sock_crt2der semicolon and spaces
    - MINOR: ssl: add ssl_{c,s}_chain_der fetch methods
    - CLEANUP: fix all duplicated semicolons
    - BUG/MEDIUM: ssl: fix the ssl-skip-self-issued-ca option
    - BUG/MINOR: ssl: ssl-skip-self-issued-ca requires >= 1.0.2
    - BUG/MINOR: stats: use strncmp() instead of memcmp() on health states
    - BUILD: makefile: don't disable -Wstringop-overflow anymore
    - BUG/MINOR: ssl: double free w/ smp_fetch_ssl_x_chain_der()
    - BUG/MEDIUM: htx: smp_prefetch_htx() must always validate the direction
    - BUG/MEDIUM: ssl: never generates the chain from the verify store
    - OPTIM: regex: PCRE2 use JIT match when JIT optimisation occured.
    - BUG/MEDIUM: ssl: does not look for all SNIs before chosing a certificate
    - CLEANUP: ssl: remove poorly readable nested ternary
4 files changed