fix(woocommerce integration): error in new-site

resolving "Could not find UOM: Nos" error in travis

(cherry picked from commit 97383716e633ae0911238fc02ffc659ad705b41a)
diff --git a/erpnext/erpnext_integrations/doctype/woocommerce_settings/woocommerce_settings.json b/erpnext/erpnext_integrations/doctype/woocommerce_settings/woocommerce_settings.json
index 3f03e59..dd3c24d 100644
--- a/erpnext/erpnext_integrations/doctype/woocommerce_settings/woocommerce_settings.json
+++ b/erpnext/erpnext_integrations/doctype/woocommerce_settings/woocommerce_settings.json
@@ -552,7 +552,6 @@
    "bold": 0,
    "collapsible": 0,
    "columns": 0,
-   "default": "Nos",
    "description": "This is the default UOM used for items and Sales orders. The fallback UOM is \"Nos\".",
    "fetch_if_empty": 0,
    "fieldname": "uom",