slaprunner: change the default port used by the monitoring web server

software/slaprunner/instance-runner.cfg

@@ -463,7 +463,7 @@ slapos-reference = master
 auto-deploy = true
 auto-deploy-instance = true
 autorun = false
-monitor-port = 9685
+monitor-port = 9684
 
 [monitor-parameters]
 port = $${slap-parameter:monitor-port}