add \n in engine labels display in docker node inspect xxx --pretty
add \n in engine labels display in docker node inspect xxx --pretty

Signed-off-by: allencloud <36603fc76d0c5a59db517817381acc1be27b9499@daocloud.io>
(cherry picked from commit ddec4c3ee4e51cb62060f752777bdd32e86607e3)
Signed-off-by: Victor Vieux <ce584ac70734cfa5a848cd28039798932c7ea675@docker.com>

medallia/docker,medallia/docker,stainboy/docker,stainboy/docker,medallia/docker,medallia/docker,stainboy/docker