Remove a parameter
Summary: D7271 added this line but the signature of function ArcanistWorkingCopyIdentity::newFromRootAndConfigFile(...) was never changed. I have no idea why it was added here and it's causing failures in facebook. I am just removing it now.
Test Plan: No idea how to test
Reviewers: wez, lifeihuang, JoelB, Blessed Reviewers, epriestley
Reviewed By: epriestley
CC: Korvin, epriestley, aran
Differential Revision: https://secure.phabricator.com/D8432