delay SW and passive event listeners

html/include/html_script_bottom_head.php

@@ -23,5 +23,10 @@ function partB(){
     $('select').material_select();
   });
 }
+if('serviceWorker' in navigator) {
+  window.addEventListener('load', function() {
+	navigator.serviceWorker.register('/sw.js');
+  });
+}
 </script>
 ";

html/index.html

@@ -140,8 +140,9 @@ När jag började informera mig om Universiteter, antagningspoäng och meritvär
 <script src="assets/js/softscrollscript.js"></script>
 <script>
 if('serviceWorker' in navigator) {
-  navigator.serviceWorker
+  window.addEventListener('load', function() {
-           .register('/sw.js');
+	navigator.serviceWorker.register('/sw.js');
+  });
 }
 </script>
 </body>