Improve Python code: address unused variables (#11049)

* Address F841 (unused variable).

* Reformat.

* Add changelog fragment.

* More cleanup.

* Remove trailing whitespace.

* Readd removed code as a comment with TODO.

plugins/modules/interfaces_file.py

@@ -172,9 +172,6 @@ def optionDict(line, iface, option, value, address_family):
 
 
 def getValueFromLine(s):
-    spaceRe = re.compile(r"\s+")
-    m = list(spaceRe.finditer(s))[-1]
-    valueEnd = m.start()
     option = s.split()[0]
     optionStart = s.find(option)
     optionLen = len(option)