AC-3 decoder is no longer GPL; update FAQ

Originally committed as revision 20776 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/faq.texi

@@ -176,14 +176,6 @@ quite logical that there is a small reduction of quality. This is not a bug.
 
 Use @file{-} as file name.
 
-@section Why does FFmpeg not decode audio in VOB files?
-
-The audio is AC-3 (a.k.a. A/52). AC-3 decoding is an optional component in FFmpeg
-as the component that handles AC-3 decoding is currently released under the GPL.
-Enable AC-3 decoding with @code{./configure --enable-gpl}. Take care: By
-enabling AC-3, you automatically change the license of libavcodec from
-LGPL to GPL.
-
 @section Why does the chrominance data seem to be sampled at a different time from the luminance data on bt8x8 captures on Linux?
 
 This is a well-known bug in the bt8x8 driver. For 2.4.26 there is a patch at