Using image from the web.

The missing `/etc/protocols` broke using images from the web. Install `netbase`.

Using image from the web.
289ce997 · nimrod · 759f84e2 · 289ce997
Commit 289ce997 authored 4 years ago by nimrod
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,6 +16,7 @@ RUN apt-get update && \
        groff \
        lmodern \
        make \
+        netbase \
        pandoc \
        texlive-extra-utils \
        texlive-fonts-extra \