[FIX] The description has to be changed only if flag set as False according what was done in other modules (see e.g module 'sale')
[FIX] typo
[FIX] Replaced description by description_sale because the latter is that used in sale order
Merge pull request #35 from tafaRU/7.0_fix_sale_line_description

[FIX] module 'sale_line_description'