fix empty ENV vars for proxy gen
fix empty ENV vars for proxy gen

Signed-off-by: Edward Raigosa <94e01cd489130787c3de55af9008bde6850741cb@hpe.com>

HewlettPackard/docker-machine-oneview,HewlettPackard/docker-machine-oneview,wenlock/docker-machine-oneview,wenlock/docker-machine-oneview,miqui/docker-machine-oneview,miqui/docker-machine-oneview,miqui/docker-machine-oneview