Since CES2017, AGL doesn't use 'layer-add-surfaces' command.
wl-shell-emultor.so is only required by 'layer-add-surfaces'.
So we can remove wl-shell-emultor from AGL.
Bug-AGL: SPEC-341
Change-Id: Icfaf91de624ed89e9640a9daf1a92b5de8912863 Signed-off-by: Ronan Le Martret <ronan.lemartret@iot.bzh>