use config for using static references to my installation

mail_templates.php

@@ -1,7 +1,8 @@
 <?php
 
 function send_mail($receiver, $subject, $body) {
-	$headers = "From: registration@cg-s.tk\r\n"
+	include("config.php");
+	$headers = "From: " . $config["register_email"] . "\r\n"
 		. "Content-Type: text/plain;charset=utf-8";
 	return mail($receiver, $subject, $body, $headers);
 }