client_max_body_size for Nginx

[NerosTie]

Issue details

I think you need to add in the docs (http://doc.wallabag.org/en/v2/user/installation.html) a line in the Nginx configuration:

# client_max_body_size XM; # allows file uploads up to X megabytes

You need that when you import a large database from an other Wallabag. If not, you have the error: 413 Request Entity Too Large.
However, this do not solve this issue: #1764

Environment

• wallabag version (or git revision) that exhibits the issue: 2.0.0
• How did you install wallabag? Via downloading the package?
• Last wallabag version that did not exhibit the issue (if applicable):
• php version: 5.x
• OS: Raspbian
• type of hosting (shared or dedicated): dedicated
• which storage system you choose at install (SQLite, MySQL/MariaDB or PostgreSQL): SQLite

Steps to reproduce/test case

Upload a large database from a previous Wallabag with the default Nginx configuration from the docs.

[j0k3r]

Feel free to submit a PR about that: https://github.com/wallabag/wallabag/blob/v2/docs/en/user/installation.rst