Domain names magic

[microspace]

I have two site behind nginx-proxy. One is flask-app, the other is wordpress site.
When I enter www.wp-site-domain.ru, browser redirects me to wp-site-domain.ru with 301 redirect
With flask site, when I enter www.flask-site.ru, browser doesn't redirect me.
Screenshot
But I used similar docker command to launch both containers!!
I can't understand where the redirect magic happens!
I launch flask app using this
docker run -d --restart=always -e VIRTUAL_HOST=*.flask-site.ru,flask-site.ru myflask
I launch wordress using this:
docker run -d --restart=always --name wordpress1 --volumes-from wordpress1_data --link wordpress1_mariadb:mysql -e VIRTUAL_HOST=*.wp-site-domain.ru,wp-site-domain.ru wordpress

[microspace]

At last I should make 301 redirection from www to nonwww?
But why wordpress site makes redirection is still mysterious for me.

[helderco]

Inspect your /etc/nginx/conf.d/default.conf file produced by docker-gen in nginx-proxy.

[microspace]

https://gist.github.com/microspace/60c7b4e59136a529d316
No clue to who does the redirection