Docker: changed from /bin/sh to /bin/bash for env variables support

- Fixes #3

amphibian-server/docker/Dockerfile

@@ -2,6 +2,15 @@ FROM jetty:9.4.35-jre11
 
 LABEL maintainer "Matija Obreza <matija.obreza@croptrust.org>"
 
+USER root
+
+# sh removes env vars it doesn't support (ones with periods)
+RUN set -ex; \
+	sed -ri 's|^#!/bin/sh$|#!/usr/bin/env bash|' /docker-entrypoint.sh
+
+# workaround for https://github.com/appropriate/docker-jetty/issues/108
+RUN rm -rf /usr/local/jetty/lib/mail
+
 ENV USER=jetty \
 	APP_DATA=/data \
 	JETTY_BASE=/var/lib/jetty/ \
@@ -9,8 +18,11 @@ ENV USER=jetty \
 
 WORKDIR ${JETTY_BASE}
 
+# Update jetty configuration
 COPY webapps ${JETTY_BASE}/webapps
+
+# Override properties
 COPY amphibian.properties ${JETTY_BASE}/resources/amphibian.properties
 
+# Add war file to the setup
 COPY ${WARFILE} ${JETTY_BASE}/webapps/amphibian.war
-