Ceph

Got the following error when processing recent merges to "mimic":

Traceback (most recent call last):
  File "/home/smithfarm/bin/backport-resolve-issue", line 579, in <module>
    backport = Backport(repo, merge_commit_string=merge)
  File "/home/smithfarm/bin/backport-resolve-issue", line 313, in __init__
    github_api_result = json.loads(json_str)
  File "/usr/lib64/python3.6/json/__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "/usr/lib64/python3.6/json/decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib64/python3.6/json/decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

It looked like the "offending" merge commit was

b7106b4e0d2 Merge pull request #30485 from sobelek/wip-41922-mimic

but there was nothing wrong with it. Upon re-run, the script proceeded without incident. I think we just need to guard this with a try-wait.