fix misprint

app/api/routes/_blockchain.py

@@ -153,7 +153,7 @@ async def s_api_v1_blockchain_send_purchase_content_message(request):
     assert request.json['license_type'] in licenses_cost
 
     return response.json({
-        'address': request.json['content_address'],
+        'address': content['encrypted_content'].json_format()['item_address'],
         'amount': str(int(licenses_cost['resale']['price'])),
         'payload': b64encode((
             begin_cell()