[FIX] account: avoid to propagate context in send by email button

There is no reason to propagate the context in those buttons.

Besides, it leads to issues concerning the email template, rendering the wrong res_id because the active_id was wrongly propagated

addons/account/account_invoice.py

@@ -426,7 +426,7 @@ class account_invoice(osv.osv):
             compose_form_id = ir_model_data.get_object_reference(cr, uid, 'mail', 'email_compose_message_wizard_form')[1]
         except ValueError:
             compose_form_id = False
-        ctx = dict(context)
+        ctx = dict()
         ctx.update({
             'default_model': 'account.invoice',
             'default_res_id': ids[0],