not allow to delete category when other transaction is using it

src/locales/en.js

@@ -325,6 +325,7 @@ export default {
         'parent transaction category not found': 'Parent transaction category is not found',
         'cannot add to secondary transaction category': 'Cannot add transaction category to secondary transaction category',
         'cannot use primary category for transaction category': 'Cannot use primary category for transaction category',
+        'transaction category is in use and cannot be deleted': 'Transaction category is in use and it cannot be deleted',
         'transaction tag id is invalid': 'Transaction tag ID is invalid',
         'transaction tag not found': 'Transaction tag is not found',
         'transaction tag name is empty': 'Transaction tag title is empty',

src/locales/zh_Hans.js

@@ -325,6 +325,7 @@ export default {
         'parent transaction category not found': '父级交易分类不存在',
         'cannot add to secondary transaction category': '不能在二级交易分类中添加',
         'cannot use primary category for transaction category': '交易分类不能使用一级分类',
+        'transaction category is in use and cannot be deleted': '交易分类正在被使用，无法删除',
         'transaction tag id is invalid': '交易标签ID无效',
         'transaction tag not found': '交易标签不存在',
         'transaction tag name is empty': '交易标签标题不能为空',