Autopilot's cleanup_dead_servers configuration not working

[sbasyal]

consul version: 1.0.0

While trying to use the Autopilot's cleanup_dead_servers Configuration, it is not working.

I tried the following configuration before bootstrapping the cluster:

    "autopilot": { 
        "cleanup_dead_servers": false,
        "last_contact_threshold": "500ms"
    },

And I can see that last_contact_threshold is set, but the cleanup_dead_servers is still false, which I can verify with the consul operator autopilot get-config command:

$ consul operator autopilot get-config
CleanupDeadServers = true
LastContactThreshold = 500ms
MaxTrailingLogs = 250
ServerStabilizationTime = 10s
RedundancyZoneTag = ""
DisableUpgradeMigration = false
UpgradeVersionTag = ""

Note that the only catch to using Autopilot Configuration is that it has to be in the leader's config when the cluster is bootstrapped for the first time. Also, if we just try to add that config to an existing cluster it won't do anything. But CleanupDeadServers seems always true unless we run consul operator autopilot set-config -cleanup-dead-servers=false.

[slackpad]

@kyhavlov can you take a look at this one? Might need to update Nomad as well.