Plane: Change throttle_override to pass in current throttle value

ArduPlane/servos.cpp

@@ -911,7 +911,7 @@ void Plane::set_servos(void)
         }
     }
 
-    uint8_t override_pct;
+    float override_pct = SRV_Channels::get_output_scaled(SRV_Channel::k_throttle);
     if (g2.ice_control.throttle_override(override_pct)) {
         // the ICE controller wants to override the throttle for starting, idle, or redline
         SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, override_pct);