Fix html to pdf conversion

After creating an automation chain to download a custom document sheet, which should convert a .html file to .pdf, using the LTS2019 in studio and installing it in a 10.10 server it works

When we change the studio version to LTS2021 and install it in a 2021.0.17 server after pressing the button it only downloads the .html file without converting it to .pdf

How to reproduce

• install the https://nos-preprod-connect.nuxeocloud.com/nuxeo/site/studio/ide?project=nuxeo-qa-sample-project configurations in a 2021.0.17 server + web-ui:3.0.3-rc.0
• create a Product document in a Workspace
• in the actions bar click in the Product Sheet button
• a .html file is downloaded - error - it should be a .pdf file with the product information

check the conversion Automation Chain here: https://nos-preprod-connect.nuxeocloud.com/nuxeo/site/studio/ide?project=nuxeo-qa-sample-project#@feature:AC_ProductSheetRendition.ops