Resubscribe correctly on MQTT reconnection
Implementing GSSAPI authentication over the current MQTT.js API is not straightforward; workarounds are necessary to ensure we can make the correct GSSAPI calls at the correct times. One of these workarounds involved disabling the MQTT.js automatic reconnection feature and instead handling reconnection manually.
Unfortunately this also disabled the automatic resubscription feature, which is causing significant problems. Adjust the workarounds to leave the automatic reconnection in place while still making the correct GSSAPI calls.