Since recently, curl fails to download the key from www.mongodb.org:
'''
$ curl --verbose https://www.mongodb.org/static/pgp/server-4.2.asc
GET /static/pgp/server-4.2.asc HTTP/1.1
Host: www.mongodb.org
User-Agent: curl/7.82.0
Accept: */*
Mark bundle as not supporting multiuse
HTTP/1.1 301 Moved Permanently
Content-Type: text/html
Date: Wed, 13 Apr 2022 20:50:19 GMT
Location: https://pgp.mongodb.com/server-4.2.asc
Connection: Keep-Alive
Content-Length: 0
'''
By default, curl would not follow redirects unless '-L' is specified.
Let's use Docker's 'ADD' command instead, like many Dockerfiles do.
Also, update the address as suggested in the server's response.
Change-Id: I9757fcce084595341b1a68822bad454b64941eb1
Related: SYS#5602
I was experiencing problems with Debian's mirrors while working on
this image, so I had to use a custom mirror list. This is a left-
over that should have been removed before merging.
Change-Id: I313bb604b09293bff8753edeefa7f78cafc9cc22
Related: SYS#5602