Change English translation for setting_issue_list_default_columns (#26501).

Patch by Go MAEDA.

git-svn-id: http://svn.redmine.org/redmine/trunk@17486 e93f8b46-1217-0410-a6f0-8f06a7374b81

config/locales/en.yml

   setting_timespan_format: Time span format
   setting_cross_project_issue_relations: Allow cross-project issue relations
   setting_cross_project_subtasks: Allow cross-project subtasks
-  setting_issue_list_default_columns: Default columns displayed on the issue list
+  setting_issue_list_default_columns: Isuses list defaults
   setting_repositories_encodings: Attachments and repositories encodings
   setting_emails_header: Email header
   setting_emails_footer: Email footer