docker: update docker push instructions
docker: update docker push instructions

git-svn-id: 6eed74fe9a15c8da84b9a8d7f2960c0406113ece@1709015 13f79535-47bb-0310-9956-ffa450edef68

roele/sling,awadheshv/sling,nleite/sling,Nimco/sling,mmanski/sling,headwirecom/sling,wimsymons/sling,cleliameneghin/sling,trekawek/sling,labertasch/sling,awadheshv/sling,JEBailey/sling,ist-dresden/sling,trekawek/sling,Nimco/sling,tteofili/sling,awadheshv/sling,wimsymons/sling,awadheshv/sling,headwirecom/sling,labertasch/sling,labertasch/sling,nleite/sling,vladbailescu/sling,labertasch/sling,mmanski/sling,trekawek/sling,anchela/sling,anchela/sling,tyge68/sling,tmaret/sling,Nimco/sling,headwirecom/sling,anchela/sling,SylvesterAbreu/sling,cleliameneghin/sling,JEBailey/sling,roele/sling,Nimco/sling,cleliameneghin/sling,tmaret/sling,ist-dresden/sling,tteofili/sling,nleite/sling,mcdan/sling,cleliameneghin/sling,mmanski/sling,mmanski/sling,tteofili/sling,mmanski/sling,mikibrv/sling,anchela/sling,mcdan/sling,SylvesterAbreu/sling,JEBailey/sling,vladbailescu/sling,SylvesterAbreu/sling,mikibrv/sling,tteofili/sling,roele/sling,tteofili/sling,SylvesterAbreu/sling,ist-dresden/sling,anchela/sling,tyge68/sling,ieb/sling,mikibrv/sling,ieb/sling,nleite/sling,roele/sling,vladbailescu/sling,headwirecom/sling,tmaret/sling,ieb/sling,wimsymons/sling,JEBailey/sling,mcdan/sling,trekawek/sling,cleliameneghin/sling,ieb/sling,mikibrv/sling,ieb/sling,mikibrv/sling,labertasch/sling,trekawek/sling,SylvesterAbreu/sling,mikibrv/sling,wimsymons/sling,roele/sling,tteofili/sling,JEBailey/sling,ieb/sling,nleite/sling,mmanski/sling,trekawek/sling,tyge68/sling,Nimco/sling,awadheshv/sling,Nimco/sling,tyge68/sling,tmaret/sling,tyge68/sling,ist-dresden/sling,awadheshv/sling,mcdan/sling,SylvesterAbreu/sling,nleite/sling,vladbailescu/sling,vladbailescu/sling,ist-dresden/sling,wimsymons/sling,wimsymons/sling,headwirecom/sling,mcdan/sling,mcdan/sling,tmaret/sling,tyge68/sling