debian: also depend on upstream docker package
debian: also depend on upstream docker package

The docker package depends on the 'docker.io' upstream debian package.
Allow 'docker-engine' as an alternate package name, which is the name of
the package in the repository on dockerproject.org.

Thanks to msl09 for this suggestion.

Close #4473
Reviewed-by: Stef Walter <8a7fbf0f15d3ad982af54ef28f5c117d2494b76c@redhat.com>

vanloswang/cockpit,harishanand95/cockpit,larskarlitski/cockpit,vanloswang/cockpit,deryni/cockpit,arilivigni/cockpit,mareklibra/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,larskarlitski/cockpit,andreasn/cockpit,andreasn/cockpit,andreasn/cockpit,sgallagher/cockpit,mareklibra/cockpit,larskarlitski/cockpit,deryni/cockpit,vanloswang/cockpit,cockpituous/cockpit,mvollmer/cockpit,larskarlitski/cockpit,sgallagher/cockpit,moraleslazaro/cockpit,larsu/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,mvollmer/cockpit,arilivigni/cockpit,SotolitoLabs/cockpit,harishanand95/cockpit,vanloswang/cockpit,harishanand95/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpituous/cockpit,cockpit-project/cockpit,garrett/cockpit,arilivigni/cockpit,dperpeet/cockpit,harishanand95/cockpit,deryni/cockpit,larsu/cockpit,xhad/cockpit,moraleslazaro/cockpit,vanloswang/cockpit,xhad/cockpit,petervo/cockpit,martinpitt/cockpit,andreasn/cockpit,stefwalter/cockpit,harishanand95/cockpit,larskarlitski/cockpit,larskarlitski/cockpit,SotolitoLabs/cockpit,petervo/cockpit,xhad/cockpit,larsu/cockpit,dperpeet/cockpit,andreasn/cockpit,stefwalter/cockpit,petervo/cockpit,Scribery/cockpit,garrett/cockpit,dperpeet/cockpit,cockpituous/cockpit,mareklibra/cockpit,cockpituous/cockpit,deryni/cockpit,arilivigni/cockpit,petervo/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,arilivigni/cockpit,deryni/cockpit,larsu/cockpit,garrett/cockpit,dperpeet/cockpit,stefwalter/cockpit,Scribery/cockpit,cockpit-project/cockpit,vanloswang/cockpit,sgallagher/cockpit,xhad/cockpit,sgallagher/cockpit,deryni/cockpit,andreasn/cockpit,michalskrivanek/cockpit,moraleslazaro/cockpit,deryni/cockpit,arilivigni/cockpit,petervo/cockpit,SotolitoLabs/cockpit,garrett/cockpit,mareklibra/cockpit,mvollmer/cockpit,xhad/cockpit,SotolitoLabs/cockpit,michalskrivanek/cockpit,petervo/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,petervo/cockpit,michalskrivanek/cockpit,sgallagher/cockpit,martinpitt/cockpit,xhad/cockpit,harishanand95/cockpit,cockpit-project/cockpit,mvollmer/cockpit,cockpit-project/cockpit,dperpeet/cockpit,cockpit-project/cockpit,andreasn/cockpit,Scribery/cockpit,larsu/cockpit,sgallagher/cockpit,garrett/cockpit,moraleslazaro/cockpit,dperpeet/cockpit,sgallagher/cockpit,xhad/cockpit,michalskrivanek/cockpit,Scribery/cockpit,vanloswang/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,stefwalter/cockpit,michalskrivanek/cockpit,moraleslazaro/cockpit,arilivigni/cockpit,mareklibra/cockpit,cockpituous/cockpit,larskarlitski/cockpit,harishanand95/cockpit,Scribery/cockpit,larsu/cockpit,dperpeet/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,mvollmer/cockpit,mareklibra/cockpit