Revert "Note about Sierra in changelog (#4369)"
Revert "Note about Sierra in changelog (#4369)"

This reverts commit c6c85f2ba930c87e1e2682caab46563fe0eed295.

keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client