cloud-init throws an error because the attribute 'run_dir' does not exist.

Issue

• cloud-init.service fails with the error "systemd: Failed to start Initial cloud-init job (pre-networking)"

• At that time, cloid-init throws the following error and traceback:

  2020-04-01 03:31:58,459 - util.py[WARNING]: failed stage init-local
  2020-04-01 03:31:58,459 - util.py[DEBUG]: failed stage init-local
  Traceback (most recent call last):
   File "/usr/lib/python2.7/site-packages/cloudinit/cmd/main.py", line 652, in status_wrapper
     ret = functor(name, args)
   File "/usr/lib/python2.7/site-packages/cloudinit/cmd/main.py", line 351, in main_init
     _maybe_persist_instance_data(init)
   File "/usr/lib/python2.7/site-packages/cloudinit/cmd/main.py", line 694, in _maybe_persist_instance_data
     init.datasource.persist_instance_data()
   File "/usr/lib/python2.7/site-packages/cloudinit/sources/__init__.py", line 304, in persist_instance_data
     json_file = os.path.join(self.paths.run_dir, INSTANCE_JSON_FILE)
  AttributeError: 'Paths' object has no attribute 'run_dir'