Catch FileNotFoundError while collecting processes

[s0undt3ch]

hook_impl.function(*args)
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib/python3.6/site-packages/pytestsysstats/plugin.py", line 158, in pytest_runtest_logreport
    children = psproc.children(recursive=True)
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib64/python3.6/site-packages/psutil/__init__.py", line 272, in wrapper
    return fun(self, *args, **kwargs)
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib64/python3.6/site-packages/psutil/__init__.py", line 931, in children
    child = Process(child_pid)
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib64/python3.6/site-packages/psutil/__init__.py", line 326, in __init__
    self._init(pid)
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib64/python3.6/site-packages/psutil/__init__.py", line 354, in _init
    self.create_time()
  File "/tmp/kitchen/testing/.nox/test-parametrized-3-crypto-none-transport-zeromq-coverage-true/lib64/python3.6/site-packages/psutil/__init__.py", line 710, in create_time
    self._create_time = self._proc.create_time()