Do not log the exception when trying to reach Connect server with org.nuxeo.connect.server.reachable=false

When the property org.nuxeo.connect.server.reachable is set to false, the system does not try to send a query to Connect to get the instance status.

However a WARN message is logged and it displays the stacktrace for the exception CanNotReachConnectServer.

Knowing that the exception CanNotReachConnectServer is only thrown when the above property is used, it's useless to log the stacktrace.