GUACAMOLE-567: Move client instability state to own flag. Actual current connection state is lost otherwise.

guacamole/src/main/webapp/app/client/controllers/clientController.js

@@ -635,7 +635,7 @@ angular.module('client').controller('clientController', ['$scope', '$routeParams
      *     otherwise.
      */
     $scope.isConnectionUnstable = function isConnectionUnstable() {
-        return $scope.client && $scope.client.clientState.connectionState === ManagedClientState.ConnectionState.UNSTABLE;
+        return $scope.client && $scope.client.clientState.tunnelUnstable;
     };
 
     // Show status dialog when connection status changes