vaultLoop: revert to SUM(amount) per user (v1 semantic)

includes/utilities.php

@@ -203,15 +203,12 @@ function vaultLoop ($name=null) {
     $pdo = getDatabaseConnection();
 
     if ($name === null) {
-        $stmt = $pdo->query(
-            'SELECT COALESCE(SUM(max_balance), 0) FROM '
-            . '(SELECT MAX(running_balance) AS max_balance FROM vault GROUP BY user)'
-        );
+        $stmt = $pdo->query('SELECT COALESCE(SUM(amount), 0) FROM vault');
 
         return (int)$stmt->fetchColumn();
     }
 
-    $stmt = $pdo->prepare('SELECT MAX(running_balance) FROM vault WHERE user = :user');
+    $stmt = $pdo->prepare('SELECT COALESCE(SUM(amount), 0) FROM vault WHERE user = :user');
     $stmt->bindValue(':user', $name);
     $stmt->execute();