Remove close alert when user is signed out (#143)

* Remove close browser tab alert when signed out

* Remove whitespace line

www/assets/app.js

@@ -55,6 +55,8 @@
 	KeyboardShortcutService.setResizeFunc($scope.resize);
 
         $scope.closeSession = function() {
+            // Remove alert before closing browser tab
+            window.onbeforeunload = null;
             $scope.socket.emit('session close');
         }