[FIX] web_editor: Avoid twice translated for static xml
[FIX] web_editor: Avoid twice translated for static xml

Avoid texts to be translated twice if some modules have the translated
value corresponding to the English source term.

To reproduce: create a translation for static xml (comment 'openerp-web')
with 'Modifier' translated by 'Tadaaa'. In french context, the 'Edit'
button in forms is translated by 'Tadaaa'.

Don't translate template in web_editor if we are in the backend because
the translations of all the modules have already been loaded and applied.

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