multi: add keep-failed-payment-attempts flag

config_builder.go

@@ -852,6 +852,7 @@ func (d *DefaultDatabaseBuilder) BuildDatabase(
 		channeldb.OptionSetBatchCommitInterval(cfg.DB.BatchCommitInterval),
 		channeldb.OptionDryRunMigration(cfg.DryRunMigration),
 		channeldb.OptionSetUseGraphCache(!cfg.DB.NoGraphCache),
+		channeldb.OptionKeepFailedPaymentAttempts(cfg.KeepFailedPaymentAttempts),
 	}
 
 	// We want to pre-allocate the channel graph cache according to what we