MAINT-1986: in TeamCity, do not reload saved hashmap_test data.

Rev b7fd7c95c571 allows a developer to debug a failure in hashmap_test 1. Once
the test fails, rerunning that test will replay the same failure to try to
permit debugging it. But that behavior is extremely undesirable under
TeamCity! In a TeamCity run, don't even check for saved data file.