test: fix order of parameters to assert.strictEqual

Usage of assert.strictEqual in test-net-server-listen-remove-callback.js
incorrectly passes the expected value as the first argument
and actual value as the second argument.

This should be reversed, per the assert documentation.

Refs: https://nodejs.org/api/assert.html#assert_assert_strictequal_actual_expected_message

test/parallel/test-net-server-listen-remove-callback.js

@@ -30,7 +30,7 @@ const server = net.createServer();
 server.on('close', function() {
   const listeners = server.listeners('listening');
   console.log('Closed, listeners:', listeners.length);
-  assert.strictEqual(0, listeners.length);
+  assert.strictEqual(listeners.length, 0);
 });
 
 server.listen(0, function() {