Allow force shrink to non-voter member

[anhanhnguyen]

Hi,

We recently tested the force shrink operation to a single member and found that it is currently not possible to shrink to a non-voter member. However, we think that in disaster recovery scenarios, it should be reasonable to recover from any member, whether a voter or non-voter.

Proposed Changes

Allow force shrink to a non-voter member, as it can be the only surviving member in a disaster recovery scenario.

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[kjnilsson]

This is a reasonable change. Thank you. Just a formatting comment.