Fix uncaught exception (os.environ -> os.getenv) in TE
Fix uncaught exception (os.environ -> os.getenv) in TE

os.environ["VAR"] is not ideal; replaced with os.getenv("VAR",default)

jonvestal/open-kilda,telstra/open-kilda,jonvestal/open-kilda,carmine/open-kilda,carmine/open-kilda,telstra/open-kilda,jonvestal/open-kilda,telstra/open-kilda,jonvestal/open-kilda,nikitamarchenko/open-kilda,carmine/open-kilda,telstra/open-kilda,nikitamarchenko/open-kilda,nikitamarchenko/open-kilda,carmine/open-kilda,jonvestal/open-kilda,telstra/open-kilda,carmine/open-kilda,telstra/open-kilda,nikitamarchenko/open-kilda,telstra/open-kilda,nikitamarchenko/open-kilda,nikitamarchenko/open-kilda,carmine/open-kilda