Don't output verbose messages when rolling back transactions

Python Stacktrace

[2022/03/21 01:00:01.649] testtools.testresult.real._StringException: Traceback (most recent call last):

[2022/03/21 01:00:01.649]   File "/data/mci/84374cf2c830f9c58cb0a15ce9722db6/wiredtiger/test/suite/wttest.py", line 508, in tearDown

[2022/03/21 01:00:01.649]     self.captureout.check(self)

[2022/03/21 01:00:01.649]   File "/data/mci/84374cf2c830f9c58cb0a15ce9722db6/wiredtiger/test/suite/wttest.py", line 116, in check

[2022/03/21 01:00:01.649]     testcase.fail('unexpected ' + self.desc + ', contains: "' +

[2022/03/21 01:00:01.649]   File "/usr/local/Cellar/python@3.9/3.9.6/Frameworks/Python.framework/Versions/3.9/lib/python3.9/unittest/case.py", line 670, in fail

[2022/03/21 01:00:01.649]     raise self.failureException(msg)

Link: https://evergreen.mongodb.com/task_log_raw/wiredtiger_macos_1014_unit_test_c833fd913a151461cb0cd90351a73a5773a4a902_22_03_20_22_45_39/0?type=T#L29784