demos: Remove doc line re: panels external to page is not supported (#8576)

Author: Robert Cochran

demos/panel/index.php

@@ -60,7 +60,7 @@
 
 		<h2>Where panel markup goes in the markup</h2>
 
-		<p>A panel must be a sibling to the header, content and footer elements inside a jQuery Mobile page. You can add the panel markup either <em>before</em> or <em>after</em> these elements, but not in between. A panel cannot be placed outside a page, but this constraint will be removed in a future version.</p>
+		<p>A panel must be a sibling to the header, content and footer elements inside a jQuery Mobile page. You can add the panel markup either <em>before</em> or <em>after</em> these elements, but not in between.</p>
 
 		<p>Here is an example of the panel before the header, content and footer in the source order:</p>