fix syntax

app.py

@@ -102,7 +102,7 @@ for i in range(len(gene_ids)):
     network_data.append({
         "data": {
             "id": gene_ids[i],
-            "label": gene_name if gene_names[i] is not None else gene_id[i]},
+            "label": gene_name if gene_names[i] is not None else gene_ids[i]},
         "position": {
             "x" : i * 10,
             "y" : i * 10}})