Fix memory leak
Fix memory leak

This memory leak caused by
https://sourceforge.jp/projects/ultramonkey-l7/scm/git/ultramonkey-l7-v3/commits/6f2218216860555ecf2243cdc51758a0e9a2f614

waiting_stc not deleted.

chi9rin/ultramonkey-l7v3,chi9rin/ultramonkey-l7v3,chi9rin/ultramonkey-l7v3,chi9rin/ultramonkey-l7v3