[FIX] account_fiscal_position_rule_sale: on_change compatibility
[FIX] account_fiscal_position_rule_sale: on_change compatibility

open-synergy/account-fiscal-rule,kmee/account-fiscal-rule,Trust-Code/account-fiscal-rule,savoirfairelinux/account-fiscal-rule,rschnapka/account-fiscal-rule,raycarnes/account-fiscal-rule,Endika/account-fiscal-rule,thinkopensolutions/account-fiscal-rule,kmee/account-fiscal-rule,ZhenIT/account-fiscal-rule,akretion/account-fiscal-rule