ISTWCMS-4704: fixing undefined index error

uw_cfg_common.module

@@ -287,7 +287,9 @@ function uw_cfg_common_preprocess_node(&$variables) {
 
       // If the layout builder style is set to full width, then set
       // the classes variable for the node and exit the loop.
-      if ($settings['layout_builder_styles_style'] == "uw_lbs_full_width") {
+      if (isset($settings['layout_builder_styles_style']) &&
+        $settings['layout_builder_styles_style'] == "uw_lbs_full_width"
+      ) {
 
         // Add a class to the node for full width on a section.
         $variables['attributes']['class'][] = 'uw-section-has-full-width';