Use a netcat with IPv6 support

Traditional `netcat` has no support for IPv6. Support is implemented in
`netcat-openbsd`, which should also be backward compatible.

Signed-off-by: Jo Vandeginste <Jo.Vandeginste@kuleuven.be>

Author: jovandeginste

docker/puppetdb/Dockerfile

@@ -69,7 +69,7 @@ COPY docker/puppetdb/docker-entrypoint.d /docker-entrypoint.d
 
 # hadolint ignore=DL3009
 RUN apt-get update && \
-    apt-get install --no-install-recommends -y ca-certificates curl dnsutils netcat && \
+    apt-get install --no-install-recommends -y ca-certificates curl dnsutils netcat-openbsd && \
     chmod +x /ssl.sh /wtfc.sh /docker-entrypoint.sh /healthcheck.sh /docker-entrypoint.d/*.sh && \
     dpkg -i dumb-init_"$DUMB_INIT_VERSION"_amd64.deb