Only use ids.whitelist.custom if the file is readable.

Author: jnorell

interface/lib/classes/ids.inc.php

@@ -68,7 +68,7 @@ public function start()
 
 		// Get whitelist
 		$whitelist_path = '/usr/local/ispconfig/security/ids.whitelist';
-		if(is_file('/usr/local/ispconfig/security/ids.whitelist.custom')) $whitelist_path = '/usr/local/ispconfig/security/ids.whitelist.custom';
+		if(is_readable('/usr/local/ispconfig/security/ids.whitelist.custom')) $whitelist_path = '/usr/local/ispconfig/security/ids.whitelist.custom';
 		if(!is_file($whitelist_path)) $whitelist_path = realpath(ISPC_ROOT_PATH.'/../security/ids.whitelist');
 
 		$whitelist_lines = file($whitelist_path);
@@ -91,7 +91,7 @@ public function start()
 
 		// Get HTML fields
 		$htmlfield_path = '/usr/local/ispconfig/security/ids.htmlfield';
-		if(is_file('/usr/local/ispconfig/security/ids.htmlfield.custom')) $htmlfield_path = '/usr/local/ispconfig/security/ids.htmlfield.custom';
+		if(is_readable('/usr/local/ispconfig/security/ids.htmlfield.custom')) $htmlfield_path = '/usr/local/ispconfig/security/ids.htmlfield.custom';
 		if(!is_file($htmlfield_path)) $htmlfield_path = realpath(ISPC_ROOT_PATH.'/../security/ids.htmlfield');
 
 		$htmlfield_lines = file($htmlfield_path);