HTTPS detection fix
More closely follow the wording of the $_SERVER['HTTPS'] description in the PHP manual, which specifies a "non-empty" value rather than "non-null"
diff --git a/system/core/Config.php b/system/core/Config.php
index 6636911..6841743 100755
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -80,7 +80,7 @@
 		{
 			if (isset($_SERVER['HTTP_HOST']))
 			{
-				$base_url = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off' ? 'https' : 'http';
+				$base_url = ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off' ? 'https' : 'http';
 				$base_url .= '://'. $_SERVER['HTTP_HOST']
 					. str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
 			}