Code review comment for lp:~axwalk/juju-core/lp1306902-ha-upgrade-take2

LGTM with two minor suggestions.

https://codereview.appspot.com/88790043/diff/1/cmd/jujud/machine.go
File cmd/jujud/machine.go (right):

https://codereview.appspot.com/88790043/diff/1/cmd/jujud/machine.go#newcode438
cmd/jujud/machine.go:438: func (a *MachineAgent)
ensureMongoServer(agentConfig agent.Config) error {
can we put this after StateWorker, so functions read generally from
higher level to lower level?

https://codereview.appspot.com/88790043/diff/1/cmd/jujud/machine.go#newcode468
cmd/jujud/machine.go:468: }
perhaps refresh agentConfig here?

(I actually think that ChangeConfig should probably always return the
new version of the agent configuration)

https://codereview.appspot.com/88790043/