Improve reliability of `strong-soap` test

[achrinza]

The following test fails quite frequently. This issue is to track improving this test.

  1) NTLM Auth tests

       should call ntlm endpoint:

     Error: Timeout of 60000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/home/travis/build/loopbackio/strong-soap/test/client-ntlm-test.js)

      at listOnTimeout (node:internal/timers:557:17)

      at processTimers (node:internal/timers:500:7)