net-mgmt/unifi5: Update to 5.6.26
- Switch to the .deb package as the distfile as requested by Ubiquiti
- Remove RESTRICTED as firmwares are no longer bundled
Changelog: https://community.ubnt.com/t5/UniFi-Updates-Blog/UniFi-5-6-26-Stable-has-been-released/ba-p/2165432