[FIX] web: Manage False in groupby title
[FIX] web: Manage False in groupby title

Before this commit, when we export a list with a groupby on
boolean, the groupby title 'False' is replaced by 'Undefined'
in xls document.

After this commit, with an export and groupby on a boolean, we
will have correct title: True and False.

X-original-commit: 7e2c7bc35f2a5b3bc22e0e6c9d3b38279cda9367

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo