openidProvider: Fix cross-site scripting.
openidProvider: Fix cross-site scripting.

If someone is able to perform a session fixation attack on the
openidProvider host, he can then make users execute scripts in that
domain.
tectronics/simplesamlphp,vivekrajenderan/simplesamlphp,vivekrajenderan/simplesamlphp,tectronics/simplesamlphp,tectronics/simplesamlphp,vivekrajenderan/simplesamlphp,vivekrajenderan/simplesamlphp,tectronics/simplesamlphp,vivekrajenderan/simplesamlphp,tectronics/simplesamlphp