调整了获取不到category时不调用getCategoryBSubCategoryDetail方法。review by 于良。

@@ -202,9 +202,9 @@ export function getCategoryBFirstSubCategoryDetail(channel_id) {
 			category = categoryList.get('lifestyle').get(0);
 		}
 
-		let category_id = category ? category.get('category_id') : "";
-		let category_name = category ? category.get('category_name') : "";
-		dispatch(getCategoryBSubCategoryDetail(category_id, category_name));
+		if(category){
+			dispatch(getCategoryBSubCategoryDetail(category.get('category_id'), category.get('category_name')));
+		}
 	};
 }