[RELEASE] Released version 2.3.1

Released version 2.3.1 with the following main changes :
    - BUG/MINOR: ssl: don't report 1024 bits DH param load error when it's higher
    - MINOR: http-htx: Add understandable errors for the errorfiles parsing
    - DOC: config: Fix a typo on ssl_c_chain_der
    - BUG/MEDIUM: ssl/crt-list: correctly insert crt-list line if crt already loaded
    - BUG/MINOR: pattern: a sample marked as const could be written
    - BUG/MINOR: lua: set buffer size during map lookups
    - BUG/MINOR: stats: free dynamically stats fields/lines on shutdown
    - BUG/MINOR: peers: Do not ignore a protocol error for dictionary entries.
    - BUG/MINOR: peers: Missing TX cache entries reset.
    - BUG/MEDIUM: peers: fix decoding of multi-byte length in stick-table messages
    - BUG/MINOR: http-fetch: Extract cookie value even when no cookie name
    - BUG/MINOR: http-fetch: Fix calls w/o parentheses of the cookie sample fetches
    - BUG/MEDIUM: check: reuse srv proto only if using same mode
    - MINOR: check: report error on incompatible proto
    - MINOR: check: report error on incompatible connect proto
    - BUG/MINOR: http-htx: Handle warnings when parsing http-error and http-errors
    - BUG/MAJOR: spoe: Be sure to remove all references on a released spoe applet
    - MINOR: spoe: Don't close connection in sync mode on processing timeout
    - BUG/MINOR: tcpcheck: Don't warn on unused rules if check option is after
    - MINOR: init: Fix the prototype for per-thread free callbacks
    - MINOR: config/mux-h2: Return ERR_ flags from init_h2() instead of a status
    - MINOR: cfgparse: tighten the scope of newnameserver variable, free it on error.
    - REGTEST: ssl: test wildcard and multi-type + exclusions
    - REGTEST: ssl: mark reg-tests/ssl/ssl_crt-list_filters.vtc as broken
    - MINOR: peers: Add traces to peer_treat_updatemsg().
    - REGTEST: make ssl_client_samples and ssl_server_samples require to 2.2
diff --git a/VERSION b/VERSION
index 276cbf9..2bf1c1c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.0
+2.3.1