With ratings far below even the network’s worst predictions, Fox could pull the plug on production for “Terminator: The Sarah Connor Chronicles” as early as this week. The network has been disappointed by “Sarah Connor’s” numbers so far this season, and some executives feel that the show is dragging down numbers for “Prison Break,” which airs as a lead-out. “Audiences just aren’t responding to the show,” a Fox source tells SyFy Portal. “Our biggest surprise are the 18-to-49s [a key advertising demographic], those numbers are in the toilet.” This would be bad news for “Sarah Connor,” which had a strong first season despite airing just nine episodes in light of the Writers Guild of America strike. The show debuted at mid-season with an 11.1 rating/16 share — the highest premiere …