doc/libavcodec: do not say multimedia streams in the title

The mention of multimedia stream sounds more like multiple
elementary media streams like video and audio multiplexed
into a multimedia container format.
Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

doc/libavcodec.texi

@@ -1113,7 +1113,7 @@ Set sample format audio decoders should prefer. Default value is
 @ignore
 
 @setfilename libavcodec
-@settitle multimedia streams decoding and encoding library
+@settitle media streams decoding and encoding library
 
 @c man begin SEEALSO
 ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1)