2.14 release notes: Add warning about changed BLOCK rule evaluation
2.14 release notes: Add warning about changed BLOCK rule evaluation

Change Ia9b57b995 changed the way how BLOCK rules are evaluated. This
should be highlighted in the release notes.

Change-Id: I4ba8b9f370f1dc658dc499b9ae4df00524b1d9c7
Signed-off-by: Edwin Kempin <d43fb6c98c97e553b671ed9a9318100f1de386e7@google.com>

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