rawexec: fix misleading log

drivers/rawexec/driver.go

@@ -477,8 +477,9 @@ func (d *Driver) SignalTask(taskID string, signal string) error {
 
 	sig := os.Interrupt
 	if s, ok := signals.SignalLookup[signal]; ok {
-		d.logger.Warn("signal to send to task unknown, using SIGINT", "signal", signal, "task_id", handle.taskConfig.ID)
 		sig = s
+	} else {
+		d.logger.Warn("signal to send to task unknown, using SIGINT", "signal", signal, "task_id", handle.taskConfig.ID)
 	}
 	return handle.exec.Signal(sig)
 }