Update install.md to fix critical issue.
Update install.md to fix critical issue.

This ensures users can download Docker without any issues.
thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io