WIP piwigo seems to make MySQL to crash

If you were performing an action on the app from the webadmin or the CLI (install, update, backup, restore, change_url...), you are on the right place!
Otherwise, the issue may be due to the app itself. Refer to its documentation or repository for help.
When in doubt, post here and we will figure it out together.
1. Delete the italic comments as you write over them below, and remove this guide.

Describe the bug

I experienced 2 mysql crash in the past week. Each type, I was browsing my pictures.

I will update this issue with info and logs

Context

Hardware: VPS bought online / Old laptop or computer / Raspberry Pi at home / Internet Cube with VPN / Other ARM board / ...
YunoHost version: x.x.x
I have access to my server: Through SSH | through the webadmin | direct access via keyboard / screen | ...
Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: no / yes
- If yes, please explain:
Using, or trying to install package version/branch:
If upgrading, current package version: can be found in the admin, or with yunohost app info $app_id

Steps to reproduce

If you performed a command from the CLI, the command itself is enough. For example:
```
sudo yunohost app install the_app
```
If you used the webadmin, please perform the equivalent command from the CLI first.
If the error occurs in your browser, explain what you did:
1. Go to '...'
2. Click on '...'
3. Scroll down to '...'
4. See error

Expected behavior

A clear and concise description of what you expected to happen. You can remove this section if the command above is enough to understand your intent.

Logs

When an operation fails, YunoHost provides a simple way to share the logs.

In the webadmin, the error message contains a link to the relevant log page. On that page, you will be able to 'Share with Yunopaste'. If you missed it, the logs of previous operations are also available under Tools > Logs.
In command line, the command to share the logs is displayed at the end of the operation and looks like yunohost log display [log name] --share. If you missed it, you can find the log ID of a previous operation using yunohost log list.

After sharing the log, please copypaste directly the link provided by YunoHost (to help readability, no need to copypaste the entire content of the log here, just the link is enough...)

If applicable and useful, add screenshots to help explain your problem.

YunoHost-Apps / piwigo_ynh