Use full domain to prevent redirects

Author: derickr

include/download-instructions/windows-native.php

@@ -3,5 +3,5 @@
 </p>
 <pre><code class="language-powershell line-numbers">
 # Download and install PHP.
-powershell -c "& ([ScriptBlock]::Create((irm 'https://php.net/install/windows.ps1'))) -Version <?= $version; ?>"
+powershell -c "& ([ScriptBlock]::Create((irm 'https://www.php.net/install/windows.ps1'))) -Version <?= $version; ?>"
 </code></pre>