Since fd75481d52, we use the survey variable to compute the
background_image_url in the survey_layout. In some cases (notably in
survey_session_code template), this layout is used without knowing the
variable 'survey'.
After this commit, the 'survey' variable is tested before usage.
Also, this commit add the o_survey_background class to the t-attf-class that
already exists on 'wrapwrap' selector. Otherwise, by having both t-att-class
and t-attf-class, only the t-att-class is kept.
Task-2703147
closesodoo/odoo#80656
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>
David Beguin
51d131663c