update Centmin Mod Nginx default index.html page

- make sure centminmod.com links to HTTPS version
- add link to how to boost performance guide

htdocs/default/index.html

@@ -93,10 +93,10 @@ <h1><strong>Centmin Mod Nginx Test Page</strong></h1>
 
 		<div class="content">
 			<div class="content-middle">
-				<p>This page is used to test the proper operation of the Centmin Mod based Nginx HTTP server after it has been installed. If you can read this page, it means that the Nginx HTTP server installed at this site is working properly.</p>
+				<p>This page is used to test the proper operation of the Centmin Mod based Nginx HTTP server after it has been installed. If you can read this page, it means that the Nginx HTTP server installed at this site is working properly. You can further boost your Centmin Mod LEMP stack performance by following configuration tips outlined in <a href="https://community.centminmod.com/threads/how-to-boost-centmin-mod-lemp-stack-performance.13776/">How to boost Centmin Mod LEMP stack performance guide</a>.</p>
 			</div>
 <div class="cmlogo">
-<p><a href="http://centminmod.com/" target="_top"><img src="cmlogo.png" width="320" height="259" border="0" align="middle" alt="CentminMod.com Nginx Auto Installer"></a></p>
+<p><a href="https://centminmod.com/" target="_top"><img src="cmlogo.png" width="320" height="259" border="0" align="middle" alt="CentminMod.com Nginx Auto Installer"></a></p>
 </div>
 			<hr />
 
@@ -114,7 +114,7 @@ <h2>If you are a member of the general public:</h2>
 				<div class="content-column-right">
 					<h2>If you are the website administrator:</h2>
 
-<p>After Centmin Mod install, follow the <a href="http://centminmod.com/getstarted.html">Getting Started Guide</a> to setup your Centmin Mod LEMP web server.</p>
+<p>After Centmin Mod install, follow the <a href="https://centminmod.com/getstarted.html">Getting Started Guide</a> to setup your Centmin Mod LEMP web server.</p>
 
 					<p>You may want to change this <tt>index.html</tt> file located within directory <tt>/usr/local/nginx/html</tt>. Note that until you do so, people visiting your website will see this page, and not your content. To prevent this page from ever being used, replace this file (<tt>index.html</tt>). </p>