Add-ons Expiring User Upgrades 2.4.3

• Fix broken "disable emails when your upgrades/subscriptions are about to expire" link for email notifications about expiring user upgrades.
• Thanks @wikislo

• Prevent errors when user email preferences have not been correctly setup by the add-on installer
• Improve installer to ensure user email preferences are setup as expected

2.2.0 - Bugfix & XF2.2 compatibility update

• Fix "Extend Upgrade button" option not being respected
• Require XenForo 2.1+
• Require php 7.0+
• Now depends on Standard Library by Xon (v1.1.0+)
• Confirm XF2.2+ support