TT#113853 Preparations for release mr8.5.4, npm not working

Trying to refresh Docker image to get it unstuck, as there are no other
obvious problems.

Change-Id: I99a88fa3dd7cc4e06d908e3e85c458ecbcf66d08

t/Dockerfile

@@ -5,7 +5,7 @@ FROM docker.mgm.sipwise.com/sipwise-buster:latest
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT 2021-03-04
+ENV REFRESHED_AT 2021-04-05
 
 # files that get-code generates
 COPY t/sources.list.d/builddeps.list /etc/apt/sources.list.d/