Wrong language for notification email

[schnello]

Steps to reproduce

1. Create a user A with language "english"
2. Create a user B with language "french"
3. User A share a file with user B and activate the "notify via email" setting

Expected behaviour

User B gets a email in the language "french"

Actual behaviour

User B gets a email in the language "english"

Server configuration

Operating system:
Ubuntu 16.04

Web server:
Apache2

Database:
mysql

PHP version:
php7

Nextcloud version: (see Nextcloud admin page)
10.01

Updated from an older Nextcloud/ownCloud or fresh install:
Updated from Owncloud

Where did you install Nextcloud from:
Git

Signing status:

Signing status

Login as admin user into your Nextcloud and access 
http://example.com/index.php/settings/integrity/failed 
paste the results here.

No errors have been found.

List of activated apps:

App list

root@uplink:/var/www/nextcloud# sudo -u www-data php occ app:list
Enabled:
  - activity: 2.3.2
  - comments: 1.0.0
  - dav: 1.0.1
  - federatedfilesharing: 1.0.1
  - files: 1.5.2
  - files_external: 1.0.2
  - files_pdfviewer: 0.8.1
  - files_sharing: 1.0.0
  - files_texteditor: 2.1
  - files_trashbin: 1.0.0
  - files_versions: 1.3.0
  - files_videoplayer: 0.9.8
  - firstrunwizard: 1.1
  - gallery: 15.0.0
  - notifications: 0.3.0
  - password_policy: 1.0.0
  - provisioning_api: 1.0.0
  - serverinfo: 1.1.1
  - survey_client: 0.1.5
  - systemtags: 1.0.2
  - templateeditor: 0.1
  - theming: 1.0.1
  - updatenotification: 1.0.1
  - workflowengine: 1.0.1
Disabled:
  - admin_audit
  - encryption
  - external
  - federation
  - files_accesscontrol
  - files_automatedtagging
  - files_retention
  - user_external
  - user_ldap
  - user_saml

The content of config/config.php:

Config report

root@uplink:/var/www/nextcloud# sudo -u www-data php occ config:list system
{
    "system": {
        "default_language": "en",
        "instanceid": "ocs19kglaiqz",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "192.168.1.210",
            "uplink.spdns.eu"
        ],
        "datadirectory": "\/var\/www\/nextcloud\/data",
        "overwrite.cli.url": "https:\/\/xxxxxxxxxxx\/",
        "htaccess.RewriteBase": "\/",
        "dbtype": "mysql",
        "version": "9.1.1.5",
        "logtimezone": "Europe\/Vienna",
        "installed": true,
        "dbname": "owncloud",
        "dbhost": "localhost",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "mail_from_address": "ubuntu.nextcloud",
        "mail_smtpmode": "sendmail",
        "mail_domain": "gmail.com",
        "maintenance": false,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "smtp.gmail.com",
        "mail_smtpport": "587",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpsecure": "tls",
        "loglevel": 2,
        "appstore.experimental.enabled": true,
        "updatechecker": false,
        "theme": "",
        "data-fingerprint": "d5e948161f4d2925d0e7d3170018b695"
    }
}

Are you using external storage, if yes which one: local/smb/sftp/...
Yes local storage

Are you using encryption: yes/no
no
Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
no

[pv2k]

Can I take this one???

[rullzer]

@pv2k all yours!

[pv2k]

Thank you 😄

[rullzer]

This became obsolete by #1929