Stop using unix.SIGUNUSED which has been removed from golang.org/x/sys
Bug-Debian:
@@ -37,7 +37,6 @@ var signalMap = map[string]syscall.Signal{
"TSTP": unix.SIGTSTP,
"TTIN": unix.SIGTTIN,
"TTOU": unix.SIGTTOU,
- "UNUSED": unix.SIGUNUSED,
"URG": unix.SIGURG,
"USR1": unix.SIGUSR1,
"USR2": unix.SIGUSR2,
