fix: return null for attribute (#20674)

diff --git a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_methods.py b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_methods.py
index 2f39dc5..3bc8db5 100644
--- a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_methods.py
+++ b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_methods.py
@@ -165,6 +165,9 @@
 	return item.name
 
 def create_manufacturer(amazon_item_json):
+	if not amazon_item_json.Product.AttributeSets.ItemAttributes.Manufacturer:
+		return None
+
 	existing_manufacturer = frappe.db.get_value("Manufacturer",
 		filters={"short_name":amazon_item_json.Product.AttributeSets.ItemAttributes.Manufacturer})
 
@@ -177,6 +180,9 @@
 		return existing_manufacturer
 
 def create_brand(amazon_item_json):
+	if not amazon_item_json.Product.AttributeSets.ItemAttributes.Brand:
+		return None
+
 	existing_brand = frappe.db.get_value("Brand",
 		filters={"brand":amazon_item_json.Product.AttributeSets.ItemAttributes.Brand})
 	if not existing_brand:
diff --git a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_mws_settings.py b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_mws_settings.py
index 249a73f..c222afb 100644
--- a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_mws_settings.py
+++ b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/amazon_mws_settings.py
@@ -7,7 +7,6 @@
 from frappe.model.document import Document
 import dateutil
 from frappe.custom.doctype.custom_field.custom_field import create_custom_fields
-from erpnext.erpnext_integrations.doctype.amazon_mws_settings.amazon_methods import get_products_details, get_orders
 
 class AmazonMWSSettings(Document):
 	def validate(self):
@@ -19,12 +18,12 @@
 
 	def get_products_details(self):
 		if self.enable_amazon == 1:
-			get_products_details()
+			frappe.enqueue('erpnext.erpnext_integrations.doctype.amazon_mws_settings.amazon_methods.get_products_details')
 
 	def get_order_details(self):
 		if self.enable_amazon == 1:
 			after_date = dateutil.parser.parse(self.after_date).strftime("%Y-%m-%d")
-			get_orders(after_date = after_date)
+			frappe.enqueue('erpnext.erpnext_integrations.doctype.amazon_mws_settings.amazon_methods.get_orders', after_date=after_date)
 
 def schedule_get_order_details():
 	mws_settings = frappe.get_doc("Amazon MWS Settings")
diff --git a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/xml_utils.py b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/xml_utils.py
index 58db669..a25a29f 100644
--- a/erpnext/erpnext_integrations/doctype/amazon_mws_settings/xml_utils.py
+++ b/erpnext/erpnext_integrations/doctype/amazon_mws_settings/xml_utils.py
@@ -33,7 +33,10 @@
 
 	def __getattr__(self, item):
 
-		d = self.__getitem__(item)
+		try:
+			d = self.__getitem__(item)
+		except KeyError:
+			return None
 
 		if isinstance(d, dict) and 'value' in d and len(d) == 1:
 			return d['value']