Fix flaky TestNoServersAvailable

  - verror.BadProtocol condition is removed by go/vcl/7540, but we still
    need it since client may get BadProtocol depending on select{} order.
  - I think the removed comment is also useful to understand the test.
    So, I recovered it.
  - I ran 1000 times for each normal/cover/race tests and there was no
    failure.

Change-Id: I767c23ff5c8955b519346051e9a3554ada23b209
1 file changed
tree: 8b376e8ca214dc62f68a2928cbd677c2f510028b
  1. lib/
  2. profiles/
  3. runtimes/
  4. security/
  5. services/
  6. tools/