Missing value auth-url required for auth plugin password

Created by: chess-knight

When I run some make target command I always get:

Missing value auth-url required for auth plugin password

It happens when I have export ENVIRONMENT instead of export OS_CLOUD in my local env.

It looks like #510 introduced it with shell ($(OPENSTACK) server list ...) command, where exporting OS_CLOUD inside Makefile seems insufficient for it.