Ignore exceptions when a resource can not be found

We silently ignore exceptions when a resource can not be found.
This may happen, when a language switcher is mounted on a 404 page but that one is not routable.
We now return an empty URL in this case instead of bailing with an HTTP 500.

src/Module/ModuleLanguageSwitcher.php

@@ -16,6 +16,7 @@
 use Hofff\Contao\LanguageRelations\LanguageRelations;
 use Hofff\Contao\LanguageRelations\Util\ContaoUtil;
 use Locale;
+use Symfony\Component\Routing\Exception\ResourceNotFoundException;
 
 use function array_filter;
 use function array_flip;
@@ -144,6 +145,8 @@ protected function compile(): void
                 $url = $page->getFrontendUrl($params, $language);
             } catch (RouteParametersException $exception) {
                 $url = '';
+            } catch (ResourceNotFoundException $exception) {
+                $url = '';
             }
 
             $item              = [];