TestListenSMTP is failing on Windows CI build

The Windows Java 1.8 build is failing on GitHub Actions due to:

[ERROR] Failures: 
[ERROR]   TestListenSMTP.validateSuccessfulInteraction:87
[ERROR]   TestListenSMTP.validateSuccessfulInteractionWithTls:150
[ERROR]   TestListenSMTP.validateTooLargeMessage:192
[ERROR] Tests run: 17, Failures: 3, Errors: 0, Skipped: 0
 

As this is not failing on any other OS and it is similar to an issue I recently saw in a PR, I believe this is due to the test runner shutdown not completing in the allowed wait duration. I don't have a local Windows system to test on, but I'll submit a PR expanding this timeout on Windows and see if the GitHub Actions pass.