That tab usually breaks in a crash. Most people just try to reglue it with gorilla glue, J.B Weld or some such. Others drill a small hole in the bottom of the frame and run a screw up through the landing gea strut, being careful not do interfer with the ESC. Still others just replace the frame. I usually try option 2, drilling a new hole in the bottom of the frame.

Hope that helps.