-make it so that apache can call airtime-check-system

utils/airtime-check-system.php

@@ -29,7 +29,8 @@ class AirtimeCheck {
     public static function ExitIfNotRoot()
     {
         // Need to check that we are superuser before running this.
-        if(exec("whoami") != "root"){
+        $user = exec("whoami");
+        if($user != "root" && $user != "www-data"){
             echo "Must be root user.\n";
             exit(1);
         }