Correctly pass worker priority from reparse script

Summary: D11044 broke the ./scripts/repository/reparse.php script.

Test Plan: ./scripts/repository/reparse.php --message --all X

Reviewers: btrahan, #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11211