Fix PEP 8 issue.

lib/ansible/modules/system/interfaces_file.py

@@ -152,6 +152,7 @@ import tempfile
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils._text import to_bytes
 
+
 def lineDict(line):
     return {'line': line, 'line_type': 'unknown'}