[maps] fix Unable to load layers from WMS capabilities for a specific…

… URL (elastic#123386)

* [maps] fix Unable to load layers from WMS spec for a specific URL

* eslint

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
(cherry picked from commit d7bce1c)

x-pack/plugins/maps/public/classes/sources/wms_source/wms_client.js

@@ -122,13 +122,17 @@ function reduceLayers(path, layers) {
     const updatedStyles = [...accumulatedCapabilities.styles];
     if (_.has(layer, 'Style[0]')) {
       updatedStyles.push(
-        createOption(path, _.get(layer, 'Style[0].Title[0]'), _.get(layer, 'Style[0].Name[0]'))
+        createOption(
+          path,
+          _.get(layer, 'Style[0].Title[0]', ''),
+          _.get(layer, 'Style[0].Name[0]', '')
+        )
       );
     }
     return {
       layers: [
         ...accumulatedCapabilities.layers,
-        createOption(path, layer.Title[0], layer.Name[0]),
+        createOption(path, _.get(layer, 'Title[0]', ''), _.get(layer, 'Name[0]', '')),
       ],
       styles: updatedStyles,
     };