fix to incorrect payment amount

Author: lodewiges

app/javascript/payment_add.js

@@ -1,7 +1,7 @@
 import Vue from 'vue/dist/vue.esm';
 import axios from 'axios';
 
-const MIN_PAYMENT_AMOUNT = 21.8;
+const MIN_PAYMENT_AMOUNT = 21;
 
 document.addEventListener('turbo:load', () => {
   axios.defaults.headers.common['X-CSRF-Token'] = document.querySelector('meta[name="csrf-token"]').getAttribute('content');