When the user specify an invalid upstream hash equivalence server in
BB_HASHSERVE_UPSTREAM notify the user that we can't connect the server.
(Bitbake rev: be45aeb9a84f30c28711e87e2d2a4a86320a8d94)
Signed-off-by: Jose Quaresma <quaresma.jose@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>