Fix build cancellation

We nowadays ignore SIGINT, so the sshd child process inherited this and ignored SIGINT as well.

Created by  Eelco Dolstra  on April 5, 2017
34UGJRDHCSPYLODA5OVN4BCD2U7A3ZLUJBHIN7WPT5NZXGMNHAQAC
In channels
upstream
main
Change contents