fix bug loading external hhb_.inc.php

if its already in an include_dir location

Author: divinity76

src/php/msgme.php

@@ -4,7 +4,7 @@
 
 namespace MsgMe;
 
-require_once ('hhb_.inc.php');
+require_once (__DIR__ . DIRECTORY_SEPARATOR . 'hhb_.inc.php');
 require_once ('MsgMeTools.php');
 interface MessageRelay {
 	public static function getRelayName(): string;