Update 'Dockerfile'

Dockerfile

@@ -6,7 +6,13 @@ RUN apt-get install -y python3 git snapraid smartmontools tzdata cron
 RUN git clone https://github.com/Chronial/snapraid-runner.git /app/snapraid-runner
 RUN chmod +x /app/snapraid-runner/snapraid-runner.py
 
-RUN echo '0 3 * * * /usr/bin/python3 /app/snapraid-runner/snapraid-runner.py -c /config/snapraid-runner.conf' > /etc/crontabs/root
+RUN echo '0 3 * * * /usr/bin/python3 /app/snapraid-runner/snapraid-runner.py -c /config/snapraid-runner.conf' > /etc/cron.d/snapraid
+
+# Give execution rights on the cron job
+RUN chmod 0644 /etc/cron.d/snapraid
+
+# Apply cron job
+RUN crontab /etc/cron.d/snapraid
 
 VOLUME /mnt /config