Wikipedia is calling for Constantine airport in Algeria ( IATA CZL) starting winter 2007 from both BSL and GVA and operated by EZS, nothing commun with serbian airport.
I dont know the reliability of this Wiki "info"
For french speakers a thread on a french forum on the subject
http://opinionsairways.forumactif.co...2007-t1940.htm
edit 19/06
Info seems vrong, althrough the Wiki pages BSL/GVA still show it, has been removed from Easyjet page.