Default expander timing

[JensOgorek]

When I created my test setup for strapping pin check, I noticed a weird boot behavior.
The core esp now has a boot delay (former 2 sec) and if the expander module's check interval is every 1 sec + the timeout again 1 sec, the delay + boot sequence is always longer and the expander esp will be restarted endlessly.

I checked the boot time and reduced the delay a bit (1.5 sec). Also, the default ping timeout is now 2 seconds, that results in a 3 seconds operation combined.

Additionally, the configure.py sometimes does not correctly get its checksum with the added delays