fix bug

defaults

@@ -3,7 +3,7 @@
     "fasta": "hg19_nochr.fa",
     "ref_dir": "oss://pgx-reference-data/hg19/",
     "chain": "hg38ToHg19.over.chain.gz",
-    "chain_dir": "oss://pgx-reference-data/reference/cosmic/",
+    "chain_dir": "oss://pgx-reference-data/reference/LiftOver/",
     "disk_size": "200",
     "cluster_config": "OnDemand bcs.a2.large img-ubuntu-vpc"
 }