Metadata batch operation may delete raftStore's instance data.

[horizonzy]

Describe the bug
The code as follow:

    private Instance locateInstance(List<Instance> instances, Instance instance) {
        int target = 0;
        while (target >= 0) {
            target = instances.indexOf(instance);
            if (target >= 0) {
                Instance result = instances.get(target);
                if (result.getClusterName().equals(instance.getClusterName())) {
                    return result;
                }
                instances.remove(target);
            }
        }
        return null;
    }

The first param instances get from raftStore, the instance's equals method be override, it judge (ip + port + ephemeral), when instance equals return true, then judge clusterName is equals.

In the code, if instance equals, but cluster name not equlas, the instance will be remove.