ctr: remove SIGUNUSED from signal map
ctr: remove SIGUNUSED from signal map

The SIGUNUSED constant was removed from golang.org/x/sys/unix in
https://go-review.googlesource.com/61771 as it is also removed from the
respective glibc headers.

This means the command

  ctr tasks kill SIGUNUSED ...

will no longer work. However, the same effect can be achieved with

  ctr tasks kill SIGSYS ...

as SIGSYS has the same value as SIGUNUSED used to have.

Signed-off-by: Tobias Klauser <9249c549618448e4c699e8032ba6c7f0d7fd4b7f@distanz.ch>

kunalkushwaha/containerd,crosbymichael/containerd,mikebrow/containerd,mikebrow/containerd,kunalkushwaha/containerd,dmcgowan/containerd,miaoyq/containerd,estesp/containerd,crosbymichael/containerd,thaJeztah/containerd,estesp/containerd,dmcgowan/containerd,AkihiroSuda/containerd,containerd/containerd,vdemeester/containerd,containerd/containerd,thaJeztah/containerd,vdemeester/containerd,miaoyq/containerd