feat: use tini

Dockerfile

@@ -28,7 +28,7 @@ ENV LC_ALL="C.UTF-8"
 # Upgrade and install dependencies
 # hadolint ignore=DL3018,DL3019
 RUN echo "@community http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories && \
-    apk add --no-cache --upgrade openjdk8-jre ca-certificates libstdc++ ffmpeg wget jq moreutils@community && \
+    apk add --no-cache --upgrade openjdk8-jre ca-certificates libstdc++ ffmpeg wget jq moreutils@community tini && \
     mkdir -p /init && \
     mkdir -p /opt/JDownloader && \
     wget -q -O /init/JDownloader.jar --user-agent="Github Docker Image Build (https://github.com/tuxpeople)" "http://installer.jdownloader.org/JDownloader.jar" && \
@@ -46,4 +46,6 @@ EXPOSE 3129
 WORKDIR /opt/JDownloader
 VOLUME /opt/JDownloader
 
+ENTRYPOINT ["/sbin/tini", "--"]
+
 CMD ["/entrypoint.sh"]