Set pingoutstanding to be false when starting the keepalive, required when reconnecting in some situations.
Set pingoutstanding to be false when starting the keepalive, required
when reconnecting in some situations.

bug: 475756

choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang,ivan4th/org.eclipse.paho.mqtt.golang,ivan4th/org.eclipse.paho.mqtt.golang,ivan4th/org.eclipse.paho.mqtt.golang