Fix typo

(transplanted from d47f438ca66c72ba98bec1e125e990944dfd6881)

move.py

@@ -875,7 +875,7 @@ class Line(ModelSQL, ModelView):
             amount = cursor.fetchone()[0]
             # SQLite uses float for SUM
             if not isinstance(amount, Decimal):
-                amout = Decimal(str(amount))
+                amount = Decimal(str(amount))
             if not currency_obj.is_zero(cursor, user,
                     party.account_receivable.currency, amount):
                 if amount > Decimal('0.0'):