stage1: take into account uid shift when creating env file
stage1: take into account uid shift when creating env file

When we run with --private-users, rkt's env file must be writable for
the root user inside the container.

sgotti/rkt,intfrr/rkt,sgotti/rkt,intfrr/rkt,joshix/rkt,tv42/rkt,akshaykarle/rkt,blixtra/rkt,chrisseto/rkt,iaguis/rkt,intfrr/rkt,mike1729/rkt,iankronquist/rkt,lee212/rkt,alban/rkt,Yhgenomics/rkt,coreos/rkt,liugenping/rkt,monstermunchkin/rkt,Shashwatsh/rkt,euank/rkt,adfernandes/rkt,euank/rkt,intelsdi-x/rkt,lucasallan/rkt,markllama/rkt,MattDees/rkt,marineam/rkt,tmrts/rkt,intelsdi-x/rkt,iaguis/rkt,sstabellini/rkt,jakon89/rkt,il9ue/rkt,joshix/rkt,alban/rkt,nhlfr/rkt,jonboulle/rkt,achanda/rkt,Yhgenomics/rkt,shobhit85/rkt,kinvolk/rkt,smarvin/rkt,sgotti/rkt,rkt/rkt,alexhersh/rkt,smarvin/rkt,kinvolk/rkt,squeed/rkt,joshix/rkt,liugenping/rkt,s-urbaniak/rkt,il9ue/rkt,lucasallan/rkt,marineam/rkt,s-urbaniak/rkt,jonboulle/rkt,kbrwn/rkt,Wilybald/rkt,coreos/rkt,dalanlan/rkt,liubq919/rkt,linki/rkt,dgonyeo/rkt,dgonyeo/rkt,tmrts/rkt,liugenping/rkt,il9ue/rkt,rkt/rkt,joshix/rkt,ybubnov/rkt,jzelinskie/rkt,jasonchaffee/rkt,MattDees/rkt,adfernandes/rkt,rkt/rkt,jonboulle/rkt,nhlfr/rkt,iaguis/rkt,monstermunchkin/rkt,cab105/rkt,mjg59/rkt,jzelinskie/rkt,mike1729/rkt,mike1729/rkt,yifan-gu/rkt,jjlakis/rkt,iankronquist/rkt,sinfomicien/rkt,lucasallan/rkt,Shashwatsh/rkt,kinvolk/rkt,sinfomicien/rkt,mjg59/rkt,endocode/rkt,krnowak/rkt,yifan-gu/rkt,Wilybald/rkt,akshaykarle/rkt,linki/rkt,jakon89/rkt,blixtra/rkt,kbrwn/rkt,alban/rkt,chrisseto/rkt,krnowak/rkt,smarvin/rkt,yifan-gu/rocket,achanda/rkt,linki/rkt,cab105/rkt,luebken/rkt,alexhersh/rkt,Wilybald/rkt,shobhit85/rkt,adfernandes/rkt,shobhit85/rkt,jasonchaffee/rkt,dalanlan/rkt,iankronquist/rkt,krnowak/rkt,rkt/rkt,markllama/rkt,sinfomicien/rkt,MattDees/rkt,squeed/rkt,intelsdi-x/rkt,marineam/rkt,alexhersh/rkt,luebken/rkt,lucasallan/rkt,markllama/rkt,squeed/rkt,lee212/rkt,Wilybald/rkt,euank/rkt,liubq919/rkt,sstabellini/rkt,kbrwn/rkt,dalanlan/rkt,lee212/rkt,Shashwatsh/rkt,mjg59/rkt,sstabellini/rkt,chrisseto/rkt,achanda/rkt,matthaias/rkt,endocode/rkt,monstermunchkin/rkt,akshaykarle/rkt,jasonchaffee/rkt,dgonyeo/rkt,yifan-gu/rocket,jjlakis/rkt,coreos/rkt,tv42/rkt,matthaias/rkt,matthaias/rkt,s-urbaniak/rkt,yifan-gu/rkt,ybubnov/rkt,kinvolk/rkt,endocode/rkt,yifan-gu/rocket,Yhgenomics/rkt,luebken/rkt,tmrts/rkt,liubq919/rkt,ybubnov/rkt,nhlfr/rkt,jzelinskie/rkt,cab105/rkt,tv42/rkt,jjlakis/rkt,blixtra/rkt,jakon89/rkt