Investigate flaky test-cluster-shared-leak (again)

[Trott]

Example failure:

• centos7-64

[claudiorodriguez]

I managed to reproduce this 50% of the time by destroying the connection like this:

      conn.on('error', function(e) {
        // ECONNRESET is OK
        if (e.code !== 'ECONNRESET')
          throw e;
      });
      setTimeout(function(){
        conn.destroy();
      }, 5);

I get the exact same error as in the log. I'm going to try some stuff to handle this case.