Don't explicitly save users when they're first seen, as they'll already be saved in the User constructor

src/main/java/net/frozenorb/apiv3/routes/users/POSTUserLogin.java

@@ -37,8 +37,8 @@ public final class POSTUserLogin implements Route {
         }
 
         if (user == null) {
+            // Will be saved in the User constructor
             user = new User(uuid, username);
-            APIv3.getDatastore().save(user);
         }
 
         Server actorServer = Server.byId(actor.getName());