Fix node ffi build (#191)

rust/ffi/node/src/index/vector.rs

@@ -97,6 +97,7 @@ fn get_index_params_builder(
                 let ivf_params = IvfBuildParams {
                     num_partitions: np,
                     max_iters,
+                    centroids: None,
                 };
                 index_builder.ivf_params(ivf_params)
             });

rust/vectordb/src/database.rs

@@ -69,7 +69,7 @@ impl Database {
     pub async fn table_names(&self) -> Result<Vec<String>> {
         let f = self
             .object_store
-            .read_dir("/")
+            .read_dir(self.uri.as_str())
             .await?
             .iter()
             .map(|fname| Path::new(fname))