Jenkinsfile: set repo and branch for DCO check as well
Jenkinsfile: set repo and branch for DCO check as well

Commit 7019b60d0d6f3d69e6ccf481ca0a912905a9c1d7 added these
env-vars to other stages, but forgot to update the DCO stage,
which also does a diff to validate commits that are in a PR.

Also adding openssh-client, for situations where the upstream
needs to be accessed through an ssh connection.

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

mahak/docker,dims/docker,ibuildthecloud/docker,djs55/docker,nalind/docker,konstruktoid/docker-1,gnailuy/docker,jvanz/docker,jameszhan/docker,ibuildthecloud/docker,jimjag/docker,kojiromike/docker,nalind/docker,moby/moby,moby/moby,flavio/docker,gnailuy/docker,flavio/docker,moul/docker,pradipd/moby,thaJeztah/docker,vdemeester/docker,SvenDowideit/docker,cpuguy83/docker,justincormack/docker,djs55/docker,docker/docker,bearstech/moby,paralin/docker,Mokolea/docker,gnailuy/docker,paralin/docker,ibuildthecloud/docker,jimjag/docker,yosifkit/docker,nawawi/docker,AkihiroSuda/docker,jameszhan/docker,Ramzec/docker,yosifkit/docker,trebonian/docker,estesp/docker,thaJeztah/docker,Ramzec/docker,ibuildthecloud/docker,estesp/docker,SvenDowideit/docker,thaJeztah/docker,Mokolea/docker,trebonian/docker,jimjag/docker,AkihiroSuda/docker,AkihiroSuda/docker,moby/moby,bearstech/moby,yosifkit/docker,konstruktoid/docker-1,kojiromike/docker,cpuguy83/docker,Mokolea/docker,moby/moby,Ramzec/docker,moul/docker,jthelin/docker,djs55/docker,mahak/docker,SvenDowideit/docker,cpuguy83/docker,trebonian/docker,nawawi/docker,docker/docker,konstruktoid/docker-1,paralin/docker,mahak/docker,konstruktoid/docker-upstream,jvanz/docker,dims/docker,flavio/docker,moul/docker,cpuguy83/docker,konstruktoid/docker-upstream,nawawi/docker,moul/docker,nawawi/docker,docker/docker,jvanz/docker,thaJeztah/docker,bearstech/moby,kojiromike/docker,mahak/docker,paralin/docker,flavio/docker,vdemeester/docker,AkihiroSuda/docker,Ramzec/docker,Mokolea/docker,konstruktoid/docker-upstream,yosifkit/docker,estesp/docker,nalind/docker,konstruktoid/docker-upstream,pradipd/moby,vdemeester/docker,ibuildthecloud/docker,nalind/docker,bearstech/moby,trebonian/docker,gnailuy/docker,dims/docker,jthelin/docker,justincormack/docker,pradipd/moby,jameszhan/docker,justincormack/docker,jimjag/docker