fix : unused imported module and typo grammar

[slowy07]

Thanks for stopping by to let us know something could be better!

PLEASE READ: If you have a support contract with Google, please create an issue in the support console instead of filing on GitHub. This will ensure a timely response.

Please run down the following list and make sure you've tried the usual "quick fixes":

• Search the issues already opened: https://github.com/googleapis/python-dialogflow/issues
• Search StackOverflow: https://stackoverflow.com/questions/tagged/google-cloud-platform+python

If you are still having issues, please be sure to include as much information as possible:

• unused imported of module callback,OrderedDict
• typo comment spelling

Environment details

• OS type and version: linux arch
• Python version: python 3.8.10
• pip version: pip 20.0.2
• google-cloud-dialogflow version: 2.7.0

Steps to reproduce

1. removed unused import module
2. fixing code grammar spelling

Code example

from typing import Awaitable, Callable, Dict, Optional, Sequence, Tuple, Union

to

from typing import Awaitable, Callable, Dict, Optional, Sequence, Tuple

Making sure to follow these steps will guarantee the quickest resolution possible.

Thanks!