allow updating domain dynamically

server.php

@@ -39,6 +39,10 @@ function show_valet_404()
     '.'.$valetConfig['domain']
 );
 
+if (strpos($siteName, 'www.') === 0) {
+    $siteName = substr($siteName, 4);
+}
+
 /**
  * Determine the fully qualified path to the site.
  */