Add missing locale string

Author: lunny

options/locale/locale_en-US.ini

@@ -2684,6 +2684,7 @@ branch.create_from = from "%s"
 branch.create_success = Branch "%s" has been created.
 branch.branch_already_exists = Branch "%s" already exists in this repository.
 branch.branch_name_conflict = Branch name "%s" conflicts with the already existing branch "%s".
+branch.branch_not_exist = Branch "%s" do not exists in this repository.
 branch.tag_collision = Branch "%s" cannot be created as a tag with same name already exists in the repository.
 branch.deleted_by = Deleted by %s
 branch.restore_success = Branch "%s" has been restored.