cat list: fix bug when adding material to existing section

cateditor/src/pages/editor/store/index.js

@@ -368,6 +368,7 @@ export const store = new Vuex.Store({
             let models = getters.sectionModels(section)
             models.push(newModel)
             foundSection = section
+            foundModels = models
             break
           }
         }