Address field set to repeatable incorrectly adds blank field groups upon save

[DevinWalker]

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Scenario: User has the repeatable address fields in a plugin or theme like so: https://gist.github.com/DevinWalker/4cfbc188b23e6e63bdcc

When saving the field a new group is created after every save:

Example 1:

Example 2:

[DevinWalker]

I stumbled upon this fix https://github.com/WebDevStudios/CMB2/issues/373 but it's really a workaround. I believe there's a core solution needed

[jtsternberg]

The snippet library is not core. I will happily accept a PR, but unfortunately don't have the time to explore this further right now.