Fix PYL-W0621 in setup.py

[reactive-firewall]

The variable f could overshadow the global var of the same name.

Issue here:

python-repo/setup.py

Lines 33 to 34 in c2194fe

	with open(str("""./{}""").format(str(filename))) as f:
	theResult = f.read()

Global defined here:

python-repo/setup.py

Lines 43 to 44 in c2194fe

	with open("""./requirements.txt""") as f:
	requirements = f.read().splitlines()