adding except blocks for task cancelation

[jhjaggars]

No description provided.

[matburt]

😢 I'm seeing the following error starting up the controller

$ receptor --debug -d ~/.receptor --node-id controller controller --stats-enable
INFO 2019-12-13 11:02:35,846 controller entrypoints Starting stats on port 8889
INFO 2019-12-13 11:02:35,849 controller controller Serving on receptor://0.0.0.0:8888
Task exception was never retrieved
future: <Task finished coro=<Receptor.watch_expire() done, defined at /c/Users/bsdma/Desktop/ansible/receptor/receptor/receptor.py:48> exception=TypeError('string indices must be integers',)>
Traceback (most recent call last):
  File "/c/Users/bsdma/Desktop/ansible/receptor/receptor/receptor.py", line 53, in watch_expire
    await buffer.expire()
  File "/c/Users/bsdma/Desktop/ansible/receptor/receptor/buffers/file.py", line 121, in expire
    ident = item["ident"]
TypeError: string indices must be integers