Updated the suggested corrective action for Docker permissions issue

[cloudxabide]

Updated the "workaround" identified for the Docker socket error. Using "chmod 0666" is less than desirable as the task would need to be repeated each time Docker is restarted.

Instead, I have updated following Docker's recommendation:

https://docs.docker.com/engine/install/linux-postinstall/#manage-docker-as-a-non-root-user