#494 Fix conversion plaintext to SHA256

- Make sure database is set up before attempting to perform the migration

src/main/java/fr/xephi/authme/process/login/AsynchronousLogin.java

@@ -220,7 +220,7 @@ public class AsynchronousLogin {
         }
     }
 
-    public void displayOtherAccounts(PlayerAuth auth) {
+    private void displayOtherAccounts(PlayerAuth auth) {
         if (!Settings.displayOtherAccounts || auth == null) {
             return;
         }