Fix Dockerfile in guides/deployment/releases.md (#4531)
Fix Dockerfile in guides/deployment/releases.md (#4531)


rafbgarcia/phoenix,rafbgarcia/phoenix,optikfluffel/phoenix,0x00evil/phoenix,0x00evil/phoenix,nshafer/phoenix,0x00evil/phoenix,nshafer/phoenix,rafbgarcia/phoenix,optikfluffel/phoenix,phoenixframework/phoenix,nshafer/phoenix,phoenixframework/phoenix,optikfluffel/phoenix,phoenixframework/phoenix