This reverts commit 95468505.

The commits break the preview, as docs is not defined in preview (while done in real printing).
Not sure what we will do, with a check on the presence of the field or not, as it was working fine before, only a wrong modification of a view made it visible.
Linked to runbot error 24276

closes odoo/odoo#132639

Signed-off-by: Florian Gilbert (flg) <flg@odoo.com>