doc/libav_merge: remove line about ADVANCED_PARSER

It's been addressed.
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Reviewed-by: Aaron Levinson <alevinsn@aracnet.com>
Signed-off-by: James Almer <jamrial@gmail.com>

doc/libav-merge.txt

@@ -105,7 +105,6 @@ Collateral damage that needs work locally:
 
 - Merge proresdec2.c and proresdec_lgpl.c
 - Merge proresenc_anatoliy.c and proresenc_kostya.c
-- Remove ADVANCED_PARSER in libavcodec/hevc_parser.c
 - Fix MIPS AC3 downmix
 - hlsenc encryption support may need some adjustment (see edc43c571d)