title: Shiny dashboard header modify dropdown
body: <p>When including a dropdown in a header with message or notification items it automatically displays the sentence "You have 1 messages" upon click. How can I only show the message but not the sentence "You have 1 messages"?</p>
  
  <p>example to reproduce below:</p>
  
  <pre><code>    ui &lt;- dashboardPage(
    dashboardHeader(dropdownMenu(type = "messages",
                                 messageItem(
                                   from = "Sales Dept",
                                   message = "Sales are steady this month."
                                 ))),
    dashboardSidebar(),
    dashboardBody()
  )
  
  server &lt;- function(input, output) { }
  
  shinyApp(ui, server)
  </code></pre>