redmine/app/views/projects/autocomplete.js.erb

<%
  s = ''
  if @projects.any?
    s = render_projects_for_jump_box(@projects, query: params[:q])
  elsif params[:q].present?
    s = content_tag('span', l(:label_no_data))
  end
%>
$('#project-jump .drdn-items.projects').html('<%= escape_javascript s %>');