Upgrade to 1.0.0-rc857

Concerns: pushword/newsletter

The consent wording of the double opt-in mail moved out of the button

The confirmation mail of a click-tracking audience now states the purpose in a muted line (newsletter.confirm.trackingHint) over a bare confirm button; the no-tracking link reads confirm (anonymized links). Only sites that overrode confirm.email.html.twig are affected: re-copy the bundle template (or add the hint line to yours), or the shortened button asks for a consent the mail no longer explains.