Commit I34e5e49ae650219f986a2b0032df65672c319ec6 tried to fix mem_limit
not passed to docker when create container for docker API vesion >=1.19
in a wrong way, this patch fixes it by passing Memory unit to host_config
Closes-Bug: #1567834
Change-Id: Id8da5e40cf165317a9a5453036490cc028bd2e0d
Co-Authored-By: Spyros Trigazis <strigazi@gmail.com>