can't run the install process of wallabag (docker / raspberry pi)

### Environment

* **Version**: latest docker image
* **Installation**: docker
* **PHP version**: n/a
* **OS**: raspberry
* **Database**: sqlite
* **Parameters**: n/a

I'm trying to install Wallabag on a raspberry pi so I know I should maybe file an issue into the [wallabag/docker](https://github.com/wallabag/docker) repository. But as I am installing Wallabg on a raspberry pi host rather that on an amd64 host, it would maybe not be the right place.

Since I don't really know if the problem comes from the Wallabag layer, the Docker layer, or the raspberry pi layer, I'm filing this issue here, and I'll move it elsewhere if needed.

My first surprise is that Wallabag do not create his own database when starting. It might not be a problem when using a standard install on a VPS, but it is definitely annoying when using containers. I don't think that the [`POPULATE_DATABASE` parameter](https://github.com/wallabag/docker#environment-variables) is effective.

The second problem is that even on a manual install, I can't make it succeed as i get an error when installing:

> PHP Warning: require(/var/www/wallabag/var/cache/pro_/ContainerDccsckm/getRouting_LoaderService.php): failed to open stream: No such file or directory in /var/www/wallabag/var/cache/prod/ContainerDccsckm/appProdProjectContainer.php on line 1430
PHP Fatal error: require(): Failed opening required '/var/www/wallabag/var/cache/pro_/ContainerDccsckm/getRouting_LoaderService.php' (include_path='.:') in /var/www/wallabag/var/cache/prod/ContainerDccsckm/appProdProjectContainer.php on line 1430

My log from install are below:
```
$ docker exec -t dd6ccaedf294 /var/www/wallabag/bin/console wallabag:install --env=prod --no-interaction

wallabag installer
==================

Step 1 of 4: Checking system requirements.
------------------------------------------

------------------------- -------- ----------------
Checked Status Recommendation
------------------------- -------- ----------------
PDO Driver (pdo_sqlite) OK!
Database connection OK!
Database version OK!
curl_exec OK!
curl_multi_init OK!
------------------------- -------- ----------------

[OK] Success! Your system can run wallabag properly.

Step 2 of 4: Setting up database.
---------------------------------

Clearing the cache...
PHP Warning: require(/var/www/wallabag/var/cache/pro_/ContainerDccsckm/getRouting_LoaderService.php): failed to open stream: No such file or directory in /var/www/wallabag/var/cache/prod/ContainerDccsckm/appProdProjectContainer.php on line 1430
PHP Fatal error: require(): Failed opening required '/var/www/wallabag/var/cache/pro_/ContainerDccsckm/getRouting_LoaderService.php' (include_path='.:') in /var/www/wallabag/var/cache/prod/ContainerDccsckm/appProdProjectContainer.php on line 1430

In appProdProjectContainer.php line 1430:

Compile Error: require(): Failed opening required '/var/www/wallabag/var/cache/pro_/ContainerDccsckm/getRouting_LoaderService.php' (include_path='.:')

cache:clear [--no-warmup] [--no-optional-warmers] [-h|--help] [-q|--quiet] [-v|vv|vvv|--verbose] [-V|--version] [--ansi] [--no-ansi] [-n|--no-interaction] [-e|--env ENV] [--no-debug] [--]
```

### What steps will reproduce the bug?