added additional check for HTTPS

I was getting an example of the following in my apache2 error log

```
[Wed May 28 23:59:12.012588 2014] [:error] [pid 25500] [client xx.xx.xx.xx:34445] PHP Notice:  Undefined index: HTTPS in /opt/jobberbase/public/page_job.php on line 71, referer: http://jobs.blah.blah/
```

This resolved it for me and I read where it may not always be set to "on" when it's HTTPS (I guess depending on the web server?).  Sending a pull request in case it helps in any way.