To remove just uwsgi-extra package itself from Debian 9 (Stretch) execute on terminal:
sudo apt-get remove uwsgi-extra
Uninstall uwsgi-extra and it's dependent packages
To remove the uwsgi-extra package and any other dependant package which are no longer needed from Debian Stretch.
sudo apt-get remove --auto-remove uwsgi-extra
If you also want to delete configuration and/or data files of uwsgi-extra from Debian Stretch then this will work:
sudo apt-get purge uwsgi-extra
To delete configuration and/or data files of uwsgi-extra and it's dependencies from Debian Stretch then execute:
sudo apt-get purge --auto-remove uwsgi-extra
More information about apt-get remove
apt-get remove is identical to install except that packages are removed instead of installed. Note that removing a package leaves its configuration files on the system. If a plus sign is appended to the package name (with no intervening space), the identified package will be installed instead of removed.