When using a closure in the "route_params" config section the metadata_map in zf-hal the config isn't re-rendered correctly when making changes

[weierophinney]

I recently opened zfcampus/zf-apigility#95. I'm not sure if it belongs here or on apigility issue tracker.

Please close as appropriate.

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Originally posted by @benwaine at zfcampus/zf-hal#96