[FIX] purchase_discount: Removes discount from supplier invoices form view, because by default it exists

Author: omar7r

Diff for: purchase_discount/__openerp__.py

@@ -36,7 +36,6 @@
     ],
     "data": [
         "views/purchase_discount_view.xml",
-        "views/account_invoice_view.xml",
         "report/purchase_discount_report.xml",
     ],
     "license": 'AGPL-3',