Update duckdb index files

.gitattributes

@@ -116,3 +116,4 @@ iwslt2017-nl-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ko-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-nl-it/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ro-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+iwslt2017-ko-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

iwslt2017-ko-en/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:45cbb1a332c233a67bb919dd57760f412e0c8792cdccede756371464aca6ffb5
+size 28061696