AP_Motors: fixed override of MOT_PWM_MIN/MAX in defaults.parm

need to check configured() not configured_in_storage()

libraries/AP_Motors/AP_MotorsMulticopter.cpp

@@ -794,7 +794,7 @@ void AP_MotorsMulticopter::save_params_on_disarm()
 // convert to PWM min and max in the motor lib
 void AP_MotorsMulticopter::convert_pwm_min_max_param(int16_t radio_min, int16_t radio_max)
 {
-    if (_pwm_min.configured_in_storage() || _pwm_max.configured_in_storage()) {
+    if (_pwm_min.configured() || _pwm_max.configured()) {
         return;
     }
     _pwm_min.set_and_save(radio_min);