Fix empty string $amount error

CRM/Utils/Number.php

@@ -117,6 +117,10 @@ class CRM_Utils_Number {
    * @throws \Brick\Money\Exception\UnknownCurrencyException
    */
   public static function formatLocaleNumeric(string $amount, $locale = NULL): string {
+    if ($amount === "") {
+      return $amount;
+    }
+
     $formatter = new \NumberFormatter($locale ?? CRM_Core_I18n::getLocale(), NumberFormatter::DECIMAL);
     $formatter->setSymbol(\NumberFormatter::DECIMAL_SEPARATOR_SYMBOL, CRM_Core_Config::singleton()->monetaryDecimalPoint);
     $formatter->setSymbol(\NumberFormatter::GROUPING_SEPARATOR_SYMBOL, CRM_Core_Config::singleton()->monetaryThousandSeparator);