Check if savedRouteForRedirect is null

If the default route redirect to a protected route the saved route for redirect is an empty string so after login the user get stuck in callback page without redirect, if we check for null instead the user get redirected to the root

projects/angular-auth-oidc-client/src/lib/auto-login/auto-login.service.ts

@@ -15,7 +15,7 @@ export class AutoLoginService {
   checkSavedRedirectRouteAndNavigate(config: OpenIdConfiguration): void {
     const savedRouteForRedirect = this.getStoredRedirectRoute(config);
 
-    if (savedRouteForRedirect) {
+    if (savedRouteForRedirect != null) {
       this.deleteStoredRedirectRoute(config);
       this.router.navigateByUrl(savedRouteForRedirect);
     }