feat: Update endpoint login

endpoints/login.post.py

@@ -10,7 +10,7 @@ async def login_demo(
     password: str = "password"
 ):
     """Demo login endpoint"""
-    user = fake_users_db.get(username)
+    user = fake_users_db.get(username
     if not user or user["password"] != password:
         raise HTTPException(status_code=400, detail="Invalid credentials")