Sometimes running the fuzzer causes assertion failures

[kenballus]

Every once in a while, especially if the Garden has just started, running the fuzzer will cause an assertion failure. This assertion is the one that ensures that the coverage information collected is not out of date.

[kenballus]

Right now I catch this and encourage the user to reload the fuzzer. In the future, I should really figure this out :)

[pajod]

I hit that a lot.. appears recoverable in <=3 retries_left once the counter is correct after the next kill(SIGUSR1)

- dump_count = f.read(1)[0]
+ if bite := f.read(1):
+     dump_count = bite[0]
+ else:
+     return None
  if dump_count != server.dump_count % 256:
-     dump_count = server.dump_count
+     server.dump_count = dump_count + 1
      return None

That is what the assignment preceding return was intended for, right? https://github.com/narfindustries/http-garden/blob/4b8e990/tools/fanout.py#L86-L87