SE-4282 add db DEFAULT CHARACTER SET

Created by: Arti3DPlayer

Description

Set DEFAULT CHARACTER SET to utf-8 for openedx_database creating command, because default character set on the server is latin1, not utf-8

According to review: https://github.com/open-craft/opencraft/pull/672#discussion_r598963816

Supporting information

JIRA Ticket SE-4282

Testing instructions

1. Pull this branch
2. Run command in terminal to recreate db: honcho run python3 manage.py recreate_db --domain=artem.stage.opencraft.hosting --admin="Your Name" --reason="Testing latest changes in pull request"

Deadline

None

Other information

@nizarmah Sorry for this, but I renamed this branch to include my name, so #751 was automatically closed.