Fix max length string validation in FormData

src/Common/FormData.php

@@ -20,7 +20,7 @@ abstract class FormData
             throw new InputValidationError("$fieldName is required.");
         } elseif (strlen($raw) < $minLength) {
             throw new InputValidationError("$fieldName is too short (minimum $minLength characters).");
-        } elseif (strlen($raw) > 100) {
+        } elseif (strlen($raw) > $maxLength) {
             throw new InputValidationError("$fieldName is too long (maximum $maxLength characters).");
         }
         return $raw;