Handle a down stream server

 <script>
 document.addEventListener('DOMContentLoaded', ev => {
   fetch('/stream-stats')
-    .then(response => response.text())
+    .then(response => {
+      if (!response.ok)
+        throw new Error('stream stats server down')
+      return response.text()
+    })
     .then(str => new window.DOMParser().parseFromString(str, "text/xml"))
     .then(data => {
       const streams = data.getElementsByTagName('stream')

         document.querySelector('#streamduration').innerHTML = Math.round(ms / 1000 / 60)
       }
     })
+    .catch(error => {
+      console.error('Error:', error.message)
+    })
 })
 </script>