install java certs before java

Author: felliott

Dockerfile

@@ -8,6 +8,8 @@ RUN usermod -d /home www-data \
  # -slim images strip man dirs, but java won't install unless this dir exists.
  && mkdir -p /usr/share/man/man1 \
  && apt-get update \
+ # HACK: work around bug in install java (dep of libreoffice)
+ && apt-get install -y ca-certificates-java \
  # mfr dependencies
  && apt-get install -y \
  git \