update error messages

config/locales/en.yml

@@ -62,8 +62,8 @@ en:
       intermediate_rent_product_name:
         blank: "Enter name of other intermediate rent product"
       startdate:
-        later_than_14_days_after: "The tenancy start date must be not be later than 14 days from today's date"
-        before_scheme_end_date: "The start date of a supported housing tenancy must be before the supported housing scheme end date"
+        later_than_14_days_after: "The tenancy start date must not be later than 14 days from today’s date"
+        before_scheme_end_date: "The tenancy start date must be before the end date for this supported housing scheme"
 
     property:
       mrcdate: