[FIX] mrp: traceback while printing BOM structure report
[FIX] mrp: traceback while printing BOM structure report

From the commit: 36b976cceeeb65fe44bf982f1c110747543d8d32
A traceback is generated while printing BOM structure
report, which is fixed in this commit.

task-2024247
closes: #34899

Signed-off-by: Simon Lejeune (sle) <1969d8dff896674c2d819e813f5e88ca826229ab@openerp.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo