Build fix and adjust array size

src/ui/MAVLinkDecoder.cc

@@ -261,7 +261,7 @@ void MAVLinkDecoder::emitFieldValue(mavlink_message_t* msg, int fieldid, quint64
     {
         // XXX this is really ugly, but we do not know a better way to do this
         mavlink_servo_output_raw_t servo;
-        mavlink_msg_rc_channels_scaled_decode(msg, &servo);
+        mavlink_msg_servo_output_raw_decode(msg, &servo);
         name = name.arg(messageInfo[msgid].name).arg(fieldName);
         name.prepend(QString("port%1_").arg(servo.port));
     }

src/ui/QGCPX4VehicleConfig.h

@@ -278,7 +278,7 @@ protected:
     UASInterface* mav;                  ///< The current MAV
     QGCUASParamManagerInterface* paramMgr;       ///< params mgr for the mav
     static const unsigned int chanMax = 18;    ///< Maximum number of channels
-    static const unsigned int chanMappedMax = 16; ///< Maximum number of mapped channels (can be higher than input channel count)
+    static const unsigned int chanMappedMax = 18; ///< Maximum number of mapped channels (can be higher than input channel count)
     unsigned int chanCount;               ///< Actual channels
     float rcMin[chanMax];                 ///< Minimum values
     float rcMax[chanMax];                 ///< Maximum values