Fix build error

Author: TobiasDeBruijn

frontend/src/views/HomeView.vue

@@ -149,8 +149,12 @@ function checkIBAN(iban: string): boolean {
   if (!/([a-zA-Z]{2}[0-9]{2})([a-zA-Z]{4}[0-9]{10})/.test(iban)){ // Check if the general format is OK
     return false;
   }
-  const numericIban = (iban.slice(4) + iban.slice(0, 4)).replace(/[A-Z]/g, char => (char.charCodeAt(0) - 55).toString()); // 11-test
-  const remainder = numericIban.split('').reduce((acc, digit) => (acc + digit) % 97, 0);
+  const numericIban = (iban.slice(4) + iban.slice(0, 4))
+    .replace(/[A-Z]/g, char => (char.charCodeAt(0) - 55).toString()); // 11-test
+  const remainder = numericIban
+    .split('')
+    .map((acc, digit) => (Number.parseInt(acc), digit))
+    .reduce((acc, digit) => (acc + digit) % 97, 0);
   return remainder === 1;
 }