remove invalid type: string from Contact property in Quote schema (#749)

Co-authored-by: Chris Mitchell <[email protected]>

Author: luke-wriglesworth

xero_accounting.yaml

@@ -24140,7 +24140,6 @@ components:
           type: string
         Contact:
           $ref: '#/components/schemas/Contact'
-          type: string
         LineItems:
           description: See LineItems
           type: array