Changelog: add 2.5 entry

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
diff --git a/Changelog b/Changelog
index 98bd2c6..c0bbbe2 100644
--- a/Changelog
+++ b/Changelog
@@ -2,6 +2,9 @@
 releases are sorted from youngest to oldest.
 
 version <next>:
+
+
+version 2.5:
 - HEVC/H.265 RTP payload format (draft v6) packetizer
 - SUP/PGS subtitle demuxer
 - ffprobe -show_pixel_formats option