use double quotes for error message.
use double quotes for error message.

[#118967073]
https://www.pivotaltracker.com/story/show/118967073

Signed-off-by: Ivan Rodriguez <489d99cb1180510ba868a41f5ab2ce6b721fdf5f@pivotal.io>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh