Update .po files
Release 1.2.4
tag: exif: avoid adding empty strings

Fixes assertion with some jpeg files
audiodecoder: Plug caps leaks

We were returning in various places without unreffing the caps, and
we were also leaking (overwriting) the caps we got from _get_current_caps()

Spotted by Haakon Sporsheim in #gstreamer
giobasesink: Implement handling of the SEEKING query