FunctionLiveEditDialog: SceneEditor: Fix crash when changing tab mode
FunctionLiveEditDialog: SceneEditor: Fix crash when changing tab mode

CF Qt bug: https://bugreports.qt.io/browse/QTBUG-18165

joepadmiraal/qlcplus,mcallegari/qlcplus,plugz/qlcplus,plugz/qlcplus,nedmech/qlcplus,kripton/qlcplus,peternewman/qlcplus,sbenejam/qlcplus,nedmech/qlcplus,plugz/qlcplus,joepadmiraal/qlcplus,kripton/qlcplus,nedmech/qlcplus,kripton/qlcplus,peternewman/qlcplus,plugz/qlcplus,sbenejam/qlcplus,plugz/qlcplus,plugz/qlcplus,peternewman/qlcplus,joepadmiraal/qlcplus,joepadmiraal/qlcplus,plugz/qlcplus,joepadmiraal/qlcplus,nedmech/qlcplus,sbenejam/qlcplus,kripton/qlcplus,mcallegari/qlcplus,mcallegari/qlcplus,kripton/qlcplus,mcallegari/qlcplus,sbenejam/qlcplus,kripton/qlcplus,mcallegari/qlcplus,nedmech/qlcplus,joepadmiraal/qlcplus,nedmech/qlcplus,mcallegari/qlcplus,kripton/qlcplus,sbenejam/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,peternewman/qlcplus,sbenejam/qlcplus,peternewman/qlcplus,peternewman/qlcplus