[ci skip] Change some log messages' level

'Class Loaded' type of messages flood log files when
log_threshold is set to 2 (debug). They're now logged
as 'info' level.

This is manually applying PR #1528, which was created
to do the same thing, but became outdated.
diff --git a/system/core/Config.php b/system/core/Config.php
index d5ce91f..3828fae 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -72,6 +72,8 @@
 	 */
 	public $_config_paths =	array(APPPATH);
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Class constructor
 	 *
@@ -82,7 +84,6 @@
 	public function __construct()
 	{
 		$this->config =& get_config();
-		log_message('debug', 'Config Class Initialized');
 
 		// Set the base_url automatically if none was provided
 		if (empty($this->config['base_url']))
@@ -101,6 +102,8 @@
 
 			$this->set_item('base_url', $base_url);
 		}
+
+		log_message('info', 'Config Class Initialized');
 	}
 
 	// --------------------------------------------------------------------