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/gitlab_protected_branch.py

@@ -112,7 +112,7 @@ class GitlabProtectedBranch:
     def protected_branch_exist(self, name):
         try:
             return self.project.protectedbranches.get(name)
-        except Exception as e:
+        except Exception:
             return False
 
     def create_or_update_protected_branch(self, name, options):