Fix squashed image name
Fix squashed image name

We were taking the name without layerID as the part before the first
dash. This is wrong because a name can have dashes.

Fix it by taking the part before the last dash.

OMWAVE/docker2aci,ChengTiesheng/docker2aci,appc/docker2aci,iaguis/docker2aci,jumpstarter-io/docker2aci,OMWAVE/docker2aci,endocode/docker2aci,pquerna/docker2aci,jsoriano/docker2aci,jsoriano/docker2aci,sgotti/docker2aci,vishvananda/docker2aci,dgonyeo/docker2aci,mclarkson/docker2aci,appc/docker2aci,vishvananda/docker2aci,jonboulle/docker2aci,dgonyeo/docker2aci