matroska: Always consider S_TEXT/UTF8 as SRT when demuxing

Reported-By: Maxim Koitsov <maksbotan@gentoo.org>

libavformat/matroska.c

@@ -55,8 +55,8 @@ const CodecTags ff_mkv_codec_tags[]={
     {"A_VORBIS"         , AV_CODEC_ID_VORBIS},
     {"A_WAVPACK4"       , AV_CODEC_ID_WAVPACK},
 
-    {"S_TEXT/UTF8"      , AV_CODEC_ID_TEXT},
     {"S_TEXT/UTF8"      , AV_CODEC_ID_SRT},
+    {"S_TEXT/UTF8"      , AV_CODEC_ID_TEXT},
     {"S_TEXT/ASCII"     , AV_CODEC_ID_TEXT},
     {"S_TEXT/ASS"       , AV_CODEC_ID_SSA},
     {"S_TEXT/SSA"       , AV_CODEC_ID_SSA},