fix pylint (#8729)

.pylintrc

@@ -8,7 +8,10 @@ jobs=0
 
 # Python code to execute, usually for sys.path manipulation such as
 # pygtk.require().
-#init-hook=
+# CERTBOT COMMENT
+# This is needed for pylint to import linter_plugin.py since
+# https://github.com/PyCQA/pylint/pull/3396.
+init-hook="import pylint.config, os, sys; sys.path.append(os.path.dirname(pylint.config.PYLINTRC))"
 
 # Profiled execution.
 profile=no