“Nikki” is no more.The WB has decided to halt production on the second season of the Bruce Helford-produced laffer, which stars Nikki Cox as a Las Vegas showgirl and Nick von Esmarch as her wrestler husband. Nineteen segs will be produced, down from the 22 the Frog had ordered from Warner Bros. Television. “Nikki” will still air as planned this week; the WB had already planned to preempt the series Feb. 3 for a “Popstars 2” marathon. It’s unclear if the skein will return after that. A total of 41 episodes will have been produced when the show wraps.