[RELEASE] Released version 1.5.11

Released version 1.5.11 with the following main changes :
    - BUG/MEDIUM: backend: correctly detect the domain when use_domain_only is used
    - MINOR: ssl: load certificates in alphabetical order
    - BUG/MINOR: checks: prevent http keep-alive with http-check expect
    - BUG/MEDIUM: Do not set agent health to zero if server is disabled in config
    - MEDIUM/BUG: Only explicitly report "DOWN (agent)" if the agent health is zero
    - BUG/MINOR: stats:Fix incorrect printf type.
    - DOC: add missing entry for log-format and clarify the text
    - BUG/MEDIUM: http: fix header removal when previous header ends with pure LF
    - BUG/MEDIUM: channel: fix possible integer overflow on reserved size computation
    - BUG/MINOR: channel: compare to_forward with buf->i, not buf->size
    - MINOR: channel: add channel_in_transit()
    - MEDIUM: channel: make buffer_reserved() use channel_in_transit()
    - MEDIUM: channel: make bi_avail() use channel_in_transit()
    - BUG/MEDIUM: channel: don't schedule data in transit for leaving until connected
    - BUG/MAJOR: log: don't try to emit a log if no logger is set
    - BUG/MINOR: args: add missing entry for ARGT_MAP in arg_type_names
    - BUG/MEDIUM: http: make http-request set-header compute the string before removal
    - BUG/MINOR: http: fix incorrect header value offset in replace-hdr/replace-value
    - BUG/MINOR: http: abort request processing on filter failure
diff --git a/VERSION b/VERSION
index f0ed379..df80819 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.10
+1.5.11