Minor fix to avoid duplicate define of SM_PATH.

src/addrbook_search_html.php

@@ -14,7 +14,9 @@
  */
 
 /* Path for SquirrelMail required files. */
-define('SM_PATH','../');
+if (! defined('SM_PATH') ) {
+	define('SM_PATH','../');
+}
 
 /* SquirrelMail required files. */
 require_once(SM_PATH . 'include/validate.php');