natural=shrubbery + shrubbery:density=* flagged as invladded key value combination

[vincentvd1]

I'm submitting a bug report

Brief Description

Areas mapped with natural=shrubbery + shrubbery:density are flagged as invalid key valued combination

What is the current behaviour, (attach relevant screenshots) ?

The changeset is flagged as invalid key valued combination

What is the expected behaviour ?

That it is not flagged. The key combination is valid and documented on wiki

How do we replicate the issue ?

1. Map an area with natural=shrubbery + shrubbery:density
2. Upload this changeset

Or, view this changeset as example: 127926739