Fix incorrect check for CAN_EDIT in macro enable/disable controller

Summary: This CAN_EDIT capability doesn't exist. `PhabricatorMacroCapabilityManage::CAPABILITY` (checked on line 15) is used instead.

Test Plan: Disabled, then re-enabled a macro.

Reviewers: hach-que, btrahan

Reviewed By: hach-que

CC: aran

Differential Revision: https://secure.phabricator.com/D7550