updated "Auto-settings rules"

extension/ui/pages/help.html

@@ -398,7 +398,8 @@
 					<li>
 						The auto-settings rules let you associate a complete or partial URL with a profile. It also allows to associate a
 						specific profile for the auto-save, or to disable it (check "display 'Auto-save profile' column"). When two or
-						more rules match a URL of a page to save, the rule with the longest URL will be chosen.
+						more rules match a URL of a page to save, the rule with the longest URL will be chosen. The special profile "-" means 
+						the current profile.
 					</li>
 					<li>
 						You can use regular expressions by prefixing the URL with "regexp:" (e.g. "regexp:.*\.com" to match all URLs