Fix the script that saves lint for a repo into the database and updates diffusion.
Summary:
It appears a change to the way the configuration was loaded into ArcanistRepositoryAPI in rARCa2285b2b broke the save_lint script.
This updates the DiffusionLintSaveRunner to use the configuration correctly, allowing the linter to run
Test Plan: cd /your/project; ../../../path/to/phabricator/scripts/repository/save_lint.php
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: aran, epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D8487