AP_Mount: Only save converted mount if mount was previously set in th…

…e first place

The mount library force configures the mount type on conversion, even if the mount was never configured in the first place

libraries/AP_Mount/AP_Mount.cpp

@@ -1024,8 +1024,8 @@ void AP_Mount::convert_params()
             // conversion is still done even if HAL_MOUNT_SERVO_ENABLED is false
             mnt_type = 7;  // (int8_t)Type::BrushlessPWM;
         }
+        _params[0].type.set_and_save(mnt_type);
     }
-    _params[0].type.set_and_save(mnt_type);
 
     // convert MNT_JSTICK_SPD to MNT1_RC_RATE
     int8_t jstick_spd = 0;