DrawIO crashes small server setup because DrawIO creates hundreds of file-versions.

[nguyenhung]

How to reproduce a crash:

• Install the latest Nextcloud (22.2.1) in a small VM instance with 1GB of RAM and 1vcore. Install DrawIO with NextCloud.
• Create a drawio file and edit it for 30 minutes. Drawio will aggressively auto-saves 200-300 versions of the file.
• Save the file and close Drawio.
• Right click on the file and open share menu. Nextcloud will automatically load the previews of all 200-300 versions in Versions tab, which will consequently crash the server. Disabling preview generation in NextCloud configs.php does not help.

Workaround: set autosave setting to off by default - nextcloudhost/settings/admin/additional

Related issues:
#126
#160