By default and in the 7.x versions and earlier, the WLC did not redirect HTTPS traffic. This means that if you open your browser and type an HTTPS address, nothing happens. You must type an HTTP address in order to get redirected to the login page which was served in HTTPS.
In Version 8.0 and later, you can enable redirection of HTTPS traffic with the CLI command config network web-auth https-redirect enable
http://www.cisco.com/c/en/us/support/docs/wireless-mobility/wlan-security/115951-web-auth-wlc-guide-00.html