Crashes when pidfile exist but process already dead

[Benys94]

Let call this zombie pidfile. I encoutered this issue when process was killed or somehow terminated but pidfile prevailed.
In this case when new process try to find process by PID from pidfile using cmd1 = psutil.Process(pid).cmdline()[0] it crashes on IndexError because no process is not found thus indexing over empty list = crash.

Proposed solution is to add IndexError into try-except block and then overwrite existing pidfile with current PID.