non-working .gitmodules files in source tree

Hi,

The FreeBSD source tree includes the file sys/contrib/openzfs/.gitmodules
since commit 1603881667360c015f6685131f2f25474fa67a72.

And a default Jenkins job using git is running is this command:
git submodule update --init --recursive

Which is failing since this commit with this error:
fatal: No url found for submodule path
'FreeBSD/sys/contrib/openzfs/scripts/zfs-images' in .gitmodules

What is the cleanest way to fix that ?
1. Should we provide a non-working .gitmodules file ?
2. Or should we document that Jenkins git plugin needs to be configured to
disable submodule to be able to work with FreeBSD sources ?
3. Other ?

Regards,

Olivier