ee engine rn: correct EE version in dm deprecation
ee engine rn: correct EE version in dm deprecation

Engine deprecation notice at engine/deprecated indicates dm deprecated in 18.09.0, which was released with EE 2.1.  Make it so in EE engine release notes.

(cherry picked from commit f0639301f4226cc221be13ff6c984aa472fe5050)

thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io