Only log url if master request exists

Author: FabianSchmick

src/Handler/EmbeddedShortcodeHandler.php

@@ -63,7 +63,7 @@ public function __invoke(ShortcodeInterface $shortcode)
                 'parameters' => json_encode($shortcode->getParameters()),
                 'renderer' => $this->renderer,
                 'shortcode' => $shortcode->getName(),
-                'url' => $this->requestStack->getMasterRequest()->getRequestUri(),
+                'url' => $this->requestStack->getMasterRequest() ? $this->requestStack->getMasterRequest()->getRequestUri() : '-',
             ]
         );