refactor: remove string array access

It is difficult to understand.

Author: kenjis

system/HTTP/SiteURIFactory.php

@@ -131,7 +131,7 @@ private function parseRequestURI(): string
 
         // Strip the SCRIPT_NAME path from the URI
         if (
-            $path !== '' && isset($this->superglobals->server('SCRIPT_NAME')[0])
+            $path !== '' && $this->superglobals->server('SCRIPT_NAME') !== ''
             && pathinfo($this->superglobals->server('SCRIPT_NAME'), PATHINFO_EXTENSION) === 'php'
         ) {
             // Compare each segment, dropping them until there is no match