filter_plugins/systemd_escape: Fix missing import sys for testing purposes

filter_plugins/systemd_escape.py

@@ -1,6 +1,7 @@
 from functools import partial
 import re
 import subprocess
+import sys
 
 from ansible.errors import AnsibleFilterError
 
@@ -30,4 +31,3 @@ class FilterModule(object):
 
 if __name__ == '__main__':
     print(systemd_escape(sys.argv[1]))
-