close #464 Fixed: 0 Money payment in invoice and bill;

Transfer,
Bill, Bill Payment, Bill Total,
Payment,
Invoice, Invoice Payment, Invoice Total,
Revenue.

resources/lang/en-GB/validation.php

@@ -102,6 +102,7 @@ return [
             'rule-name' => 'custom-message',
         ],
         'invalid_currency' => 'The :attribute code is invalid.',
+        'invalid_amount'   => 'The amount :attribute is invalid.',
     ],
 
     /*