use correct magic var in php entry scripts to hold script folder structure independent of call folder

fix php socket location in postinst script

api/settings.php

@@ -1,5 +1,5 @@
 <?php
-require_once './src/handlers/Settings.php';
+require_once __DIR__ . '/src/handlers/Settings.php';
 
 $sett = new Settings();
 $sett->handleAction();