compatible with drupal 9

Hi, 
while install drupal 9 site, we get below errors:
![image](https://user-images.githubusercontent.com/1829399/115948615-ba0e9400-a501-11eb-8545-b9bef6df91de.png)
![image](https://user-images.githubusercontent.com/1829399/115948646-ecb88c80-a501-11eb-9b88-541e46ef392a.png)

![image](https://user-images.githubusercontent.com/1829399/115948568-60a66500-a501-11eb-9cb9-b922eaffa726.png)
