test: refactor pummel/test-net-connect-econnrefused

* Reduce ROUNDS and ATTEMPTS_PER_ROUND by half to avoid spurious test
  failures as a result of side effects from other tests. (For my local
  setup, test-keep-alive seems to cause this test to fail with ETIMEDOUT
  and/or EADDRNOTAVAIL. It would seem to be a result of throttling.
  Reducing the pummel-iness of that test and this one seems to solve the
  problem.)
* Apply capitalization and punctuation to comment.

PR-URL: #25485
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/pummel/test-net-connect-econnrefused.js

@@ -20,14 +20,14 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-// verify that connect reqs are properly cleaned up
+// Verify that connect reqs are properly cleaned up.
 
 const common = require('../common');
 const assert = require('assert');
 const net = require('net');
 
-const ROUNDS = 10;
-const ATTEMPTS_PER_ROUND = 100;
+const ROUNDS = 5;
+const ATTEMPTS_PER_ROUND = 50;
 let rounds = 1;
 let reqs = 0;