Merge #923

923: Update command for user import r=mergify[bot] a=zoldar

## What type of PR?

Documentation update.

## What does this PR do?

Updates obsolete user import command example.

## Related issue(s)

Refs https://github.com/Mailu/Mailu/issues/849
Refs https://github.com/Mailu/Mailu/pull/877#discussion_r255300087

## Prerequistes
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.

- [x] ~In case of feature or enhancement: documentation updated accordingly~
- [x] ~Unless it's docs or a minor change: place entry in the [changelog](CHANGELOG.md), under the latest un-released version.~


Co-authored-by: Adrian Gruntkowski <adrian.gruntkowski@gmail.com>

docs/cli.rst

@@ -39,7 +39,7 @@ primary difference with simple `user` command is that password is being imported
 
 .. code-block:: bash
 
-  docker-compose run --rm admin python manage.py user --hash_scheme='SHA512-CRYPT' myuser example.net '$6$51ebe0cb9f1dab48effa2a0ad8660cb489b445936b9ffd812a0b8f46bca66dd549fea530ce'
+  docker-compose run --rm admin flask mailu user-import myuser example.net '$6$51ebe0cb9f1dab48effa2a0ad8660cb489b445936b9ffd812a0b8f46bca66dd549fea530ce' 'SHA512-CRYPT'
 
 user_delete
 ------------