When the timeshift recording reaches the end time of the start event,
the progress bar and the end time no longer shows any useful
information.
From this version the current live event is used to calculate the
progress bar and the end time.
With commit 8a04a17 an error was introduced which did not take the global
timers into account in the timeshift replay.
thanks to @machtnix at vdr-portal.de for finding the bug