Update llx_accounting_account.key.sql

htdocs/install/mysql/tables/llx_accounting_account.key.sql

@@ -19,6 +19,7 @@
 
 
 ALTER TABLE llx_accounting_account ADD INDEX idx_accounting_account_fk_pcg_version (fk_pcg_version);
+ALTER TABLE llx_accounting_account ADD INDEX idx_accounting_account_account_number (account_number);
 
 ALTER TABLE llx_accounting_account ADD CONSTRAINT fk_accounting_account_fk_pcg_version  FOREIGN KEY (fk_pcg_version)    REFERENCES llx_accounting_system (pcg_version);