Fix the visibility of PhutilDaemon::run methods
Summary: Ref T6822. This method is only called from PhutilDaemon::execute() and can be made protected.
Test Plan: See D11404.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T6822
Differential Revision: https://secure.phabricator.com/D11405