Revert "Enlarge the race window for some test cases"

This reverts commit 2a84d2597469d272794a1fb5fb43c6260f335195.

Broke regression test on test_hwm.cpp.
Revert "Add code to investigate data race"

This reverts commit 5e0facda17b986943f0fe40a2dc6c98611655c35.
Merge pull request #1001 from hintjens/master

These commits broke regression tests, so I'm reverting them.