Remove the Secure cookie option and choose automatically

The "Cookie secure" options prevent the possibility to access the board both over HTTP and over HTTPS.

I suggest to drop this option altogether and just set the cookie "secure" or "not secure" automatically, switching on the exchange being over HTTP or HTTPS.

Topic: https://www.phpbb.com/community/viewtopic.php?f=46&t=2130175&p=13568281#p13568281