Upload logo is not working

### CKAN Version if known (or site URL)

2.8+ 
### Please describe the expected behaviour
When uploading logo from config page, we should see new logo on the portal

### Please describe the actual behaviour
Logo is not uploaded 

### What steps can be taken to reproduce the issue? 
Go to 
https://beta.ckan.org/ckan-admin/config

Upload an image 
Update config