prodimage: bump to focal

Change-Id: I502ef4bbc593dae4db900eb10dc4ad93daad3985
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1382
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/devtools/prodimage/Dockerfile b/devtools/prodimage/Dockerfile
index 9cdf8a2..df20145 100644
--- a/devtools/prodimage/Dockerfile
+++ b/devtools/prodimage/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:bionic-20190515
+FROM ubuntu:focal
 
 RUN set -e -x ;\
     sed -i 's/archive/pl.archive/' /etc/apt/sources.list
@@ -7,6 +7,7 @@
     export DEBIAN_FRONTEND=noninteractive ;\
     apt-get -y update ;\
     apt-get -y install \
+        lib32stdc++6 \
         ca-certificates \
         gnupg2 \
         rsync \