Error 500 with importing from Wallabag v1

[ddeimeke]

Issue details

Please provide issue details here.
Remember, this is not a place to ask questions. For that, go to http://gitter.im/wallabag/wallabag.

Environment

• wallabag version (or git revision) that exhibits the issue: v2 (2.0.0)
• How did you install wallabag? Via composer create-project or by downloading the package? git clone, php bin/console wallabag:install --env=prod
• Last wallabag version that did not exhibit the issue (if applicable):
• php version: 5.6.20
• OS: CentOS 7.2.1511, recent patch level
• type of hosting (shared or dedicated): decicated server
• which storage system you choose at install (SQLite, MySQL/MariaDB or PostgreSQL): MySQL

Steps to reproduce/test case

Please provide necessary steps for reproduction of this issue, or better the
reduced test case (without any external dependencies, if possible).

Export from Wallabag 1.9.1 fails to be imported into Wallabag 2.0.0, nothing found in the Apache error.log

[nicosomb]

Duplicate of #1764
Can you have a look to this #1764 (comment) please?