Changed extends to implements
ApiKeyUserProvider should implements UserProviderInterface
bug #3477 Api key user provider should use "implements" instead of "extends" (skowi)

This PR was merged into the 2.4 branch.

Discussion
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Api key user provider should use "implements" instead of "extends"

Commits
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f1c1273 ApiKeyUserProvider should implements UserProviderInterface
f39686a Changed extends to implements