use "Due date" instead of "Due to" in English version 'field_effective_date' (#14680, #22315)

git-svn-id: http://svn.redmine.org/redmine/trunk@15413 e93f8b46-1217-0410-a6f0-8f06a7374b81

config/locales/en-GB.yml

@@ -262,7 +262,7 @@ en-GB:
   field_admin: Administrator
   field_last_login_on: Last connection
   field_language: Language
-  field_effective_date: Due to
+  field_effective_date: Due date
   field_password: Password
   field_new_password: New password
   field_password_confirmation: Confirmation

config/locales/en.yml

@@ -286,7 +286,7 @@ en:
   field_admin: Administrator
   field_last_login_on: Last connection
   field_language: Language
-  field_effective_date: Due to
+  field_effective_date: Due date
   field_password: Password
   field_new_password: New password
   field_password_confirmation: Confirmation