Avoid that InfoBarTimeshif state is shown when coming from audioselection

And possibly other instantiated infobar screens. This was intrododuced by
commit
https://github.com/OpenSPA/dvbapp/commit/41d923f9a1704933b52c55238431201fc9abb2ee
and solved by only doing this the first time when the InfoBar is executed.

Thanks Beeker for the early reporting
http://openpli.org/forums/topic/34480-osd-player-na-verlaten-hoofdaudiomenu/