[Evolution] sticky filter

[Alain Dubois <Alain Dubois hec be>]

In Evo 1.4.4, I created  a filter on sender that moved incoming mails to
a specified folder. It worked.
Then I decided to delete that filter. It doesn't show anymore in the
fiter's list but it still works (mails from that sender still get moved
to the specified folder).
How do I get rid of this "sticky" filter ?