Update TransportSecurityState::AddHPKP comment: dynamic PKP is not persisted.

PKP persistence was removed as part of https://crrev.com/230996f183bc6eb2f8ec2a39f7d19f9d6267ec84

Bug: 779166
Change-Id: Ic8dcc6a983f08418465b301e99e0bd226521e073
Reviewed-on: https://chromium-review.googlesource.com/c/1297286
Reviewed-by: David Benjamin <davidben@chromium.org>
Commit-Queue: Matt Mueller <mattm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602508}
1 file changed