Bug in clean-css with pseudo selectors

I noticed a bug, related to clean-css that removes the spaces in pseudo selectors. The bug causes the following selector to be wrongly transformed. 
`:not(#message label)` becomes `:not(#messagelabel)` causing the rule to be uneffective.
The issue has been fixed with the latest clean-css releases. Is there a chance for you to update the package? Thank you
