Fix uninitialized variable in AppSettings causing a Segfault

src/Settings/AppSettings.cc

@@ -78,6 +78,7 @@ AppSettings::AppSettings(QObject* parent)
     , _savePathFact                         (NULL)
     , _autoLoadMissionsFact                 (NULL)
     , _useChecklistFact                     (NULL)
+    , _advancedLinkSettingsFact             (NULL)
     , _mapboxTokenFact                      (NULL)
     , _esriTokenFact                        (NULL)
     , _defaultFirmwareTypeFact              (NULL)