Set standalone to true explicitly in config_sample.yml

Setting environment variable STANDALONE to true results in a string
value for cfg.standalone, which fails "cfg.standalone is True" condition.

Docker-DCO-1.1-Signed-off-by: bqbn <bqbn@openken.com> (github: dmp42)
Bump version

Docker-DCO-1.1-Signed-off-by: Mangled Deutz <olivier@webitup.fr> (github: dmp42)