Update passport-tests.ts

https://stackoverflow.com/questions/40349987/how-to-suppress-typescript-error-ts2533-object-is-possibly-null-or-undefine

types/passport/passport-tests.ts

@@ -148,7 +148,7 @@ declare global {
 
 app.use((req: express.Request, res: express.Response, next: (err?: any) => void) => {
     if (req.user) {
-        req.user.username = "hello user";
+        req.user!.username = "hello user";
     }
     next();
 });