Fixed is_zip check

Author: tkakar

src/vitessce/wrappers.py

@@ -1252,13 +1252,13 @@ def __init__(self, adata_path=None, adata_url=None, adata_store=None, adata_arti
             self.is_remote = False
             self.is_store = False
             self.zarr_folder = 'anndata.zarr'
-            if is_zip and '.zip' in str(adata_path):
+            if is_zip is None and '.zip' in str(adata_path):
                 self.is_zip = True
         elif adata_url is not None or adata_artifact is not None:
             self.is_remote = True
             self.is_store = False
             self.zarr_folder = None
-            if is_zip and '.zip' in str(adata_url):
+            if is_zip is None and '.zip' in str(adata_url):
                 self.is_zip = True
             # Store artifacts on AbstractWrapper.artifacts for downstream access,
             # e.g. in lamindb.save_vitessce_config