phrik: Change WantedBy=default.target to WantedBy=multi-user.target

This seems more proper as default.target is not a real target that
services should require. multi-user.target is the sensible default
for such services.

roles/phrik/files/phrik.service

@@ -9,4 +9,4 @@ ProtectSystem=full
 User=phrik
 
 [Install]
-WantedBy=default.target
+WantedBy=multi-user.target