Remove UID from all users

We don't need preconfigure it. This way it won't change the UID of
existing accounts, having to recreate them in the process.

data_bags/users/kare.json

@@ -4,6 +4,5 @@
     "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCw0I82gT8R4tpsqWGovLyjm2SR2F863MqNz224h3h/wl0xA5Eu0eRro+ELLv2hoebqQbcMsb89X5+7ObhDRar+b7tzDlXq4x+ECkAy6WbDSmBp3kNVd7muT4c9Zw7UxKsIvIm1ven1TkJ3UG80o6PyGiAUlBj4puIQwhp7OVknVutBBe8Rpp4f6BEuWluwpnPxc3KSaGhhr9p10xeX69cfspH40r8vHpI0zp19O5GpfYSOEH64UbwRpN2QypNB8ISmDHFsNGwdz0Ba4qrEOSGU9GveyOcsvEtt630/0fHqtbPBovOYu/FJISQZya2tofDig4EngBCJNfsPCbXFHtlp greg@karekinian.com"
   ],
   "groups": ["sysadmin", "systemd-journal"],
-  "uid": 2001,
   "shell": "\/bin\/bash"
 }