Set env vars as mandatory to push to DB

Set env vars as mandatory to push to DB

Now env vars are mandatory in push_results_to_db. It avoids testing
programs to check them even if they are useless from their points of
view.
The related getters aren't removed to help debugging via
logger_test_results which could be run without report.

Change-Id: Iadb94319529f5ec4230fb62042511948183b93ed
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>