Token Auth By Cookie NullPointerException

**error code class:package com.webank.wedatasphere.linkis.gateway.security.token.TokenAuthentication**

```
def tokenAuth(gatewayContext: GatewayContext): Boolean = {
    ...
    var token = gatewayContext.getRequest.getHeaders.get(TOKEN_KEY)(0)
    var tokenUser = gatewayContext.getRequest.getHeaders.get(TOKEN_USER_KEY)(0)
    ...
  }