[2.3.5] Android App given error 500

When configuring the Android app, the app gives error

```API access test failed
Unknown error: com.di72nn.stuff.wallabag.apiwrapper.exceptions.UnsuccessfulResponseException: HTTP response: 500
```

Even though the client ID and secret are fetched.

Only way to fix this problem is to run `chown -R nobody:nobody bin app/config vendor data web var` from inside the docker container for wallabag.

This should not be necessary

Relevant logs:

```2019/01/27 19:18:25 [error] 252#252: *838 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught UnexpectedValueException: The stream or file "/var/www/wallabag/var/logs/prod.log" could not be opened: failed to open stream: Permission denied in /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:107
wallabag_1 | 2019/01/27 19:18:25 [error] 252#252: *838 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught UnexpectedValueException: The stream or file "/var/www/wallabag/var/logs/prod.log" could not be opened: failed to open stream: Permission denied in /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:107
wallabag_1 | Stack trace:
wallabag_1 | #0 /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Handler/AbstractProcessingHandler.php(39): Monolog\Handler\StreamHandler->write(Array)
wallabag_1 | #1 /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Handler/FingersCrossedHandler.php(123): Monolog\Handler\AbstractProcessingHandler->handle(Array)
wallabag_1 | #2 /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Logger.php(344): Monolog\Handler\FingersCrossedHandler->handle(Array)
wallabag_1 | #3 /var/www/wallabag/vendor/monolog/monolog/src/Monolog/Logger.php(735): Monolog\Logger->addRecord(500, 'Uncaught PHP Ex...', Array)
wallabag_1 | #4 /var/www/wallabag/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php(102): Monolog\Logger->critical('Uncaught PHP Ex...', Array)
wallabag_1 | #5 /var/" while reading response header from upstream, client: 192.168.32.3, server: _, request: "GET /api/version.json HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "wallabag.bnolet.me"
wallabag_1 | 192.168.32.3 - - [27/Jan/2019:19:18:25 +0000] "GET /api/version.json HTTP/1.1" 500 31 "-" "okhttp/3.8.1"
```