test: add debugging for callbacks in test-https-foafssl.js

The test is timing out once in a very long while on Windows CI. It is
unclear where the test gets stuck, so add more debugging statements to
try to locate it.

Refs: nodejs#24397

test/parallel/test-https-foafssl.js

@@ -56,7 +56,7 @@ const server = https.createServer(options, common.mustCall(function(req, res) {
   assert.strictEqual(cert.exponent, exponent);
   assert.strictEqual(cert.modulus, modulus);
   res.writeHead(200, { 'content-type': 'text/plain' });
-  res.end(body);
+  res.end(body, () => { console.log('stream finished'); });
   console.log('sent response');
 }));
 
@@ -74,8 +74,11 @@ server.listen(0, function() {
     const message = data.toString();
     const contents = message.split(CRLF + CRLF).pop();
     assert.strictEqual(body, contents);
-    server.close();
-    console.log('server closed');
+    server.close((e) => {
+      assert.ifError(e);
+      console.log('server closed');
+    });
+    console.log('server.close() called');
   });
 
   client.stdin.write('GET /\n\n');