MKV: fix typo in metadata

modules/demux/mkv/matroska_segment.cpp

@@ -240,7 +240,7 @@ static const struct {
                      {vlc_meta_Publisher,   "PUBLISHER"},
                      {vlc_meta_URL,         "URL"},
                      {vlc_meta_TrackNumber, "PART_NUMBER"},
-                     {vlc_meta_Date,        "DATE_RELEASE"},
+                     {vlc_meta_Date,        "DATE_RELEASED"},
                      {vlc_meta_Title,       NULL},
 };