Azure AD Connect: Fix broken link in fed-whatis

[AndKjell]

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[msftclas]

Hi @AndKjell, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

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[PRmerger]

@AndKjell : Thanks for your contribution to the Azure documentation! The author, @anandyadavMSFT, has been notified to review your proposed change.

[anandyadavMSFT]

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