[FIX] invoice_webkit - css thead (lp:c2c-addons/6.1  rev 83)
[FIX] invoice_webkit - css thead
(lp:c2c-addons/6.1  rev 83)

amoya-dx/account-invoice-reporting,Eficent/account-invoice-reporting,vrenaville/account-invoice-reporting,raycarnes/account-invoice-reporting,Endika/account-invoice-reporting,charbeljc/account-invoice-reporting,massot/account-invoice-reporting,damdam-s/account-invoice-reporting,hurrinico/account-invoice-reporting