v7.7-a7: **Page Optimize** Improved dummy CSS replacement rule.

Author: Hai Zheng

src/optimize.cls.php

@@ -20,7 +20,7 @@ class Optimize extends Base {
 
 	const ITEM_TIMESTAMP_PURGE_CSS = 'timestamp_purge_css';
 
-	const DUMMY_CSS_REGEX = "#<link rel=['\"]stylesheet['\"] id=['\"]litespeed-cache-dummy-css['\"] href=['\"].+assets/css/litespeed-dummy\.css[?\w.=-]*['\"][ \w='\"/]*>#isU";
+	const DUMMY_CSS_REGEX = "#<link [ \w='\"/]*id=['\"]litespeed-cache-dummy-css['\"] href=['\"].+assets/css/litespeed-dummy\.css[?\w.=-]*['\"][ \w='\"/]*>#isU";
 
 	private $content;
 	private $content_ori;