Bump psycopg2-binary in /{{cookiecutter.app_name}}/requirements

Bumps [psycopg2-binary](https://github.com/psycopg/psycopg2) from 2.8.3 to 2.8.4.
- [Release notes](https://github.com/psycopg/psycopg2/releases)
- [Changelog](https://github.com/psycopg/psycopg2/blob/master/NEWS)
- [Commits](https://github.com/psycopg/psycopg2/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

{{cookiecutter.app_name}}/requirements/prod.txt

@@ -8,7 +8,7 @@ click>=7.0
 # Database
 Flask-SQLAlchemy==2.4.1
 SQLAlchemy==1.3.10
-psycopg2-binary==2.8.3
+psycopg2-binary==2.8.4
 
 # Migrations
 Flask-Migrate==2.5.2