Fixes spelling error in settings log on auth provider pages

Summary: The settings logs on auth provider pages shows "enabled accont linking" instead of "enabled account linking."

Test Plan: Checked the copy on the settings log.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12164