only test raw matrix dimensionality if it exists

cellxgene_schema_cli/cellxgene_schema/validate.py

@@ -802,7 +802,7 @@ def _validate_seurat_convertibility(self):
                 self.is_seurat_convertible = False
 
         # Check to make sure raw.var has the same dimensionality as raw.X
-        if get_num_vars_in_raw_matrix(self.adata) != get_num_vars_in_raw_var(self.adata):
+        if self.adata.raw and get_num_vars_in_raw_matrix(self.adata) != get_num_vars_in_raw_var(self.adata):
             self.warnings.append(
                 f"This dataset cannot be converted to the .rds (Seurat v4) format. "
                 f"There is a mismatch in the number of variables in the raw matrix and the raw var key-indexed "