Bump base image...

Bump base image (https://github.com/discourse/discourse_docker/commit/faa7b961bbd3f7426927a8188770e190c4d2e77a)

Dockerfile

 # Check https://github.com/discourse/discourse_docker/blob/master/launcher
-FROM discourse/base:2.0.20210217-2235
+FROM discourse/base:2.0.20210415-1332
 
 LABEL maintainer="Discourse Administrators <discourse-admins@cern.ch>" \
       io.openshift.expose-services="8080,3000,6379:http"