Update duckdb index files

.gitattributes

@@ -83,3 +83,4 @@ iwslt2017-it-nl/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-it-ro/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-it-ro/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-it-ro/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
+iwslt2017-ja-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

iwslt2017-ja-en/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d5455d10ba076122fcc04e9fb2daef37deb6ddacad5c44f5788f76d61df1abfd
+size 26488832