jigasi: fix autoscaler sidecar config for shutdown url (#1784)

jigasi/rootfs/defaults/autoscaler-sidecar.config

@@ -9,6 +9,7 @@ export TERMINATE_SCRIPT="/opt/jitsi/shutdown.sh"
 export ENABLE_REPORT_STATS=true
 export POLLING_URL="{{ .Env.AUTOSCALER_URL  }}/sidecar/poll"
 export STATUS_URL="{{ .Env.AUTOSCALER_URL }}/sidecar/status"
+export SHUTDOWN_URL="{{ .Env.AUTOSCALER_URL }}/sidecar/shutdown"
 export STATS_RETRIEVE_URL="http://localhost:{{ $JIGASI_STATS_PORT }}/about/stats"
 export STATS_REPORT_URL="{{ .Env.AUTOSCALER_URL }}/sidecar/stats"
 export ASAP_SIGNING_KEY_FILE="{{ .Env.AUTOSCALER_SIDECAR_KEY_FILE }}"