Fix deprecation notice when attempting to resolve a non-static page (#37

)

Co-authored-by: Luke Towers <github@luketowers.ca>

Plugin.php

@@ -285,7 +285,7 @@ protected function extendCmsRenderer(): void
              * Get rendered content
              */
             $contents = Controller::instance()->getPageContents($page);
-            if (strlen($contents)) {
+            if (!empty($contents)) {
                 return $contents;
             }
         });