Manual:$wgSecureLogin/es

Detalles
If true, forces users to authenticate using https when they come from http, but only if you use a protocol-relative URL in  (otherwise this setting is ignored).

From 1.22 on, use  to set   false by default if you want HTTP users to stay on HTTP after login by default.

Basado en una idea de George Herbert en wikitech-l: wikitech-l/2010-October/050071.html.

Deberás configurar $wgServer como sigue.