Update system.php

system/library/system.php

@@ -268,7 +268,7 @@
 					return false;
 
 				case 'ip':
-					if(!preg_match("/^(25[0-5]|2[0-4][0-9]|[0-1][0-9]{2}|[0-9]{2}|[0-9])(\.(25[0-5]|2[0-4][0-9]|[0-1][0-9]{2}|[0-9]{2}|[0-9])){3}$/", $val))
+					if(!preg_match('/^(25[0-5]|2[0-4][0-9]|[0-1][0-9]{2}|[0-9]{2}|[0-9])(\.(25[0-5]|2[0-4][0-9]|[0-1][0-9]{2}|[0-9]{2}|[0-9])){3}$/', $val))
 						return true;
 
 					return false;