[BUGFIX] Add check for empty format configuration

Changing the condition in the ViewHelper was mentioned in PR #713.
This won't fix the problem that configuration was not available
in backend module.

Relates: #732
Closes: #713

Author: d-g-codappix

Classes/ViewHelpers/Format/CurrencyViewHelper.php

@@ -102,7 +102,7 @@ public function render(): string
 
         $settings = $this->templateVariableContainer->get('settings');
 
-        if ($settings && $settings['format'] && $settings['format']['currency']) {
+        if (isset($settings['format']['currency'])) {
             $currencyFormat = $settings['format']['currency'];
 
             if (!isset($currencySign) && isset($currencyFormat['currencySign'])) {