added support for custom port, fixed the time zone issue caused by cron

dockerfiles/start.sh

@@ -1,8 +1,14 @@
 #!/bin/sh
 /home/pi/pialert/dockerfiles/user-mapping.sh
 
+# if custom variables not set we do not need to do anything
+if [ -n "${TZ}" ]; then  
+  sed -ie "s|Europe/London|${TZ}|g" /home/pi/pialert/install/pialert.cron   
+  crontab < /home/pi/pialert/install/pialert.cron
+fi
+if [ -n "${PORT}" ]; then  
+  sed -ie 's/= 20211/= '${PORT}'/g' /etc/lighttpd/lighttpd.conf 
+fi
 
-#chmod -R 755 /var/www/html/pialert
-#chmod -R o+w /home/pi/pialert/db
 /etc/init.d/lighttpd start
 cron -f