add missing variable $constpref

Close #9

Author: fiammybe

language/english/admin.php

@@ -1,4 +1,6 @@
 <?php
+$constpref = '_AM_IFORUM';
+
 	define("_AM_IFORUM_FORUMCONF", "Forum Configuration");
 	define("_AM_IFORUM_ADDAFORUM", "Add a Forum");
 	define("_AM_IFORUM_SYNCFORUM", "Sync forum");