Update Logger.php

Change log level number to match RFC 5424. Enabling threshold on 'debug' level is same as show all messages. This is what developer wants on debugging stage

Author: sugenganthos

system/Log/Logger.php

@@ -73,10 +73,10 @@ class Logger implements LoggerInterface
 		'alert'		 => 2,
 		'critical'	 => 3,
 		'error'		 => 4,
-		'debug'		 => 5,
-		'warning'	 => 6,
-		'notice'	 => 7,
-		'info'		 => 8,
+		'warning'	 => 5,
+		'notice'	 => 6,
+		'info'	 	 => 7,
+		'debug'		 => 8,
 	];
 
 	/**