Changed cron.php frequency from 15m to 5m

Dockerfile

@@ -8,7 +8,7 @@ RUN apt-get -q update && \
     apt-get -qq install \
     cron \
     nano-tiny && \
-    echo "*/15 * * * * su - www-data -s /bin/bash -c \"php -f /var/www/html/cron.php\"" | crontab - && \
+    echo "*/5 * * * * su - www-data -s /bin/bash -c \"php -f /var/www/html/cron.php\"" | crontab - && \
     sed -i '2 i\service cron start' /entrypoint.sh && \
     apt-get purge -y nano-tiny && \
     rm -rf /var/lib/apt/lists/* && \