Update to fix ticket #850 (#2845)
Update to fix ticket #850 (#2845)

* Update to fix ticket #850

Suggested fix was based on this [ticket](https://github.com/docker/docker.github.io/issues/850) and reference to this popular [Stackoverflow](http://stackoverflow.com/questions/33562109/docker-command-cant-connect-to-docker-daemon) issue.

* Update linux-postinstall.md

anweiss/docker.github.io,shubheksha/docker.github.io,thaJeztah/docker.github.io,phiroict/docker,shin-/docker.github.io,joeuo/docker.github.io,shubheksha/docker.github.io,bdwill/docker.github.io,thaJeztah/docker.github.io,JimGalasyn/docker.github.io,bdwill/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,shubheksha/docker.github.io,docker/docker.github.io,joeuo/docker.github.io,shin-/docker.github.io,bdwill/docker.github.io,londoncalling/docker.github.io,JimGalasyn/docker.github.io,docker/docker.github.io,bdwill/docker.github.io,phiroict/docker,phiroict/docker,johnstep/docker.github.io,thaJeztah/docker.github.io,johnstep/docker.github.io,JimGalasyn/docker.github.io,johnstep/docker.github.io,shubheksha/docker.github.io,bdwill/docker.github.io,thaJeztah/docker.github.io,phiroict/docker,londoncalling/docker.github.io,shin-/docker.github.io,JimGalasyn/docker.github.io,joeuo/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,anweiss/docker.github.io,johnstep/docker.github.io,anweiss/docker.github.io,johnstep/docker.github.io,docker/docker.github.io,joeuo/docker.github.io,phiroict/docker,anweiss/docker.github.io,shin-/docker.github.io,shin-/docker.github.io,JimGalasyn/docker.github.io,joeuo/docker.github.io,shubheksha/docker.github.io,docker/docker.github.io,anweiss/docker.github.io