If OS_CLOUD is set, it may cause install to fail

[mdujava]

osia/osia/installer/executor.py

Line 37 in a4c0767

additional_env = environ.copy()

When OS_CLOUD is set to different cloud than defined in a selected env from settings.yaml, pre-install steps (image upload, adding dns entry for a floating IP) are done in correct cloud, but openshift-install fails as it will use wrong cloud (defined by OS_CLOUD env variable) from openstack clouds.yaml, image would not be found.