(apologies for bumping an old thread but I just figured out how to solve this) This is what I did:
1. Boot to recovery and disable SIP, reboot
2. Copy /var/db/locationd/clients.plist to Desktop (probably good practice to make a backup of this), open in Xcode, and remove the Dictionary "93EB3F36-1BE6-4DE0-9B33-09827243F8F0:icom.apple.Safari:"
3. Copy that file such that it overwrites /var/db/locationd/clients.plist
4. Reboot again and go to some website that will prompt Safari for location
5. Recovery again to re-enable SIP