test: use strictEqual() domain-http

did this at nina 2016 na code and learn event

PR-URL: #9996
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-domain-http-server.js

@@ -88,7 +88,7 @@ function next() {
 }
 
 process.on('exit', function() {
-  assert.equal(serverCaught, 2);
-  assert.equal(clientCaught, 2);
+  assert.strictEqual(serverCaught, 2);
+  assert.strictEqual(clientCaught, 2);
   console.log('ok');
 });