dnac_config.py doesn't exist

[RuthCattell]

An issue found by Presidio as follows:
"A bit of feedback, it looks like there is a mismatch between the lab directions and the code for the DNA Center labs. All the DNAC labs say to import your config with:
from dnac_config import DNAC, DNAC_PORT, DNAC_USER, DNAC_PASSWORD
but in reality dnac_config.py doesn’t exist, and instead the “Verify Your Lab Environment” lab has the students populating a dictionary in env_lab.py."

[kiskander]

I think it's safe to remove this instruction from the Authentication lab, this lab is also a Standalone lab part of Getting Started with DNAC module.

so we can remove

dnac_config is a python file that contains Cisco DNA Center configuration info. In this case we are using our DevNet Sandbox

import requests
from requests.auth import HTTPBasicAuth
from dnac_config import DNAC, DNAC_PORT, DNAC_USER, DNAC_PASSWORD

from the Lab in the DNE and we will be good