Rights log changes:

Rights log changes:
* Adding "(none)" notice also if the third parameter (new groups) is empty (when desysoping someone, for example).
* Adding the "(none)" notice also in the recent changes.
* Adding the "(none)" notice only if the action is "rights/rights", to prevent future potential incompatibility, if we add other log actions in "rights" log, or if an extension does so.
* First checking if the parameter is null before checking if it's empty, to prevent an ugly notice appears when using Makesysop (apparently not in Wikimedia servers, I think notices are disabled there).