Revert "use non-root user in docker image"

This reverts commit 9b4ee24a0e.

Unfortunately, this change breaks backwards compatibility.
(Due to permission issues, existing bind mounts wouldn't work anymore
and users would need to manually adapt permissions in order to get it
working again). Will revert this change for now, until a backwards
compatible solution is found

Dockerfile

@@ -41,8 +41,6 @@ RUN cd /tmp/signal-cli-rest-api-src && swag init && go build
 # Start a fresh container for release container
 FROM adoptopenjdk:11-jre-hotspot
 
-RUN useradd -ms /bin/bash signal
-
 COPY --from=buildcontainer /tmp/signal-cli-rest-api-src/signal-cli-rest-api /usr/bin/signal-cli-rest-api
 COPY --from=buildcontainer /tmp/signal-cli /opt/signal-cli
 
@@ -50,12 +48,6 @@ RUN ln -s /opt/signal-cli/bin/signal-cli /usr/bin/signal-cli
 RUN mkdir -p /signal-cli-config/
 RUN mkdir -p /home/.local/share/signal-cli
 
-RUN chown -R signal:signal /home/.local/share/signal-cli
-RUN chmod u+rwx /home/.local/share/signal-cli
-
-USER signal
-WORKDIR /home/signal
-
 EXPOSE 8080
 
 ENTRYPOINT ["signal-cli-rest-api"]