fix "watching port" in docs (#3)

Co-authored-by: tyler36 <[email protected]>

README.md

@@ -19,7 +19,7 @@ This service can be used with any project type. The examples below are Drupal-sp
   - Drupal Test Traits
     - Ensure you have a working site that has the `weitzman/drupal-test-traits` Composer package.
     - `ddev exec -d /var/www/html/web "../vendor/bin/phpunit --bootstrap=../vendor/weitzman/drupal-test-traits/src/bootstrap-fast.php --printer '\Drupal\Tests\Listeners\HtmlOutputPrinter' ../vendor/weitzman/drupal-test-traits/tests/ExampleSelenium2DriverTest.php"`
-- On your host, browse to https://[DDEV SITE URL]:7910 (password: `secret`) to watch tests run (neat!).
+- On your host, browse to https://[DDEV SITE URL]:7900 (password: `secret`) to watch tests run (neat!).
 
 ## Contribute
 
@@ -28,4 +28,3 @@ This service can be used with any project type. The examples below are Drupal-sp
 ## Maintainer
 
 - Contributed and maintained by [@weitzman](https://github.com/weitzman).
-