Remove "CODEC_CAP_EXPERIMENTAL added" entry from the Changelog.

That's an API related change, no point to advertise it in the
Changelog.

Originally committed as revision 24822 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -8,7 +8,6 @@ version <next>:
 - low overhead Ogg muxing
 - MMS-TCP support
 - VP8 de/encoding via libvpx
-- CODEC_CAP_EXPERIMENTAL added
 - Demuxer for On2's IVF format
 - Pictor/PC Paint decoder
 - HE-AAC v2 decoder