Mac: update file sharing folder list and error message
Mac: update file sharing folder list and error message

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@docker.com>

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