Decrease default session timeout

Even if it’s possible to make it using configuration setting it’s fine (just not to change ruby code ). Or is it possible during setup specify (these properties): discourse/config/site_settings.yml at main · discourse/discourse · GitHub
maximum_session_age:
default: 1440
min: 1
max: 175200

Because we’re set it up using docker and I’m not sure whether these props will take affect.