suricata.yaml: mark unified2 as deprecated

suricata.yaml.in

@@ -290,47 +290,11 @@ outputs:
         # flowints.
         #- metadata
 
-  # alert output for use with Barnyard2
+  # deprecated - unified2 alert format for use with Barnyard2
   - unified2-alert:
       enabled: no
-      filename: unified2.alert
-
-      # File size limit.  Can be specified in kb, mb, gb.  Just a number
-      # is parsed as bytes.
-      #limit: 32mb
-
-      # By default unified2 log files have the file creation time (in
-      # unix epoch format) appended to the filename. Set this to yes to
-      # disable this behaviour.
-      #nostamp: no
-
-      # Sensor ID field of unified2 alerts.
-      #sensor-id: 0
-
-      # Include payload of packets related to alerts. Defaults to true, set to
-      # false if payload is not required.
-      #payload: yes
-
-      # HTTP X-Forwarded-For support by adding the unified2 extra header or
-      # overwriting the source or destination IP address (depending on flow
-      # direction) with the one reported in the X-Forwarded-For HTTP header.
-      # This is helpful when reviewing alerts for traffic that is being reverse
-      # or forward proxied.
-      xff:
-        enabled: no
-        # Two operation modes are available, "extra-data" and "overwrite". Note
-        # that in the "overwrite" mode, if the reported IP address in the HTTP
-        # X-Forwarded-For header is of a different version of the packet
-        # received, it will fall-back to "extra-data" mode.
-        mode: extra-data
-        # Two proxy deployments are supported, "reverse" and "forward". In
-        # a "reverse" deployment the IP address used is the last one, in a
-        # "forward" deployment the first IP address is used.
-        deployment: reverse
-        # Header name where the actual IP address will be reported, if more
-        # than one IP address is present, the last IP address will be the
-        # one taken into consideration.
-        header: X-Forwarded-For
+      # for further options see:
+      # https://suricata.readthedocs.io/en/suricata-5.0.0/configuration/suricata-yaml.html#alert-output-for-use-with-barnyard2-unified2-alert
 
   # a line based log of HTTP requests (no alerts)
   - http-log: