systemd: add KNOT_CONF_MAX_SIZE env variable to ExecStart parameters

distro/common/knot.service

@@ -11,12 +11,13 @@ Group=knot
 CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_SETPCAP
 AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_SETPCAP
 ExecStartPre=/usr/sbin/knotc conf-check
-ExecStart=/usr/sbin/knotd
+ExecStart=/usr/sbin/knotd -m "$KNOT_CONF_MAX_SIZE"
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=on-abort
 LimitNOFILE=1048576
 TimeoutStopSec=300
 Environment="KNOT_ZONE_LOAD_TIMEOUT_SEC=180"
+Environment="KNOT_CONF_MAX_SIZE=512"
 
 [Install]
 WantedBy=multi-user.target