fix: publish items

- Pass image data as a json
- ignore duplicates while creating Hub Tracked Item
diff --git a/erpnext/hub_node/api.py b/erpnext/hub_node/api.py
index 0c9af1a..a8958ab 100644
--- a/erpnext/hub_node/api.py
+++ b/erpnext/hub_node/api.py
@@ -56,7 +56,7 @@
 			'item_code': item_code,
 			'hub_category': item.get('hub_category'),
 			'image_list': item.get('image_list')
-		}).insert()
+		}).insert(ignore_if_duplicate=True)
 
 	try:
 		hub_settings = frappe.get_doc('Hub Settings')