Fix JS issue on Special:ViewRelationshipRequests.

Accepting or rejecting a friend/foe request wasn't possible, because
jQuery( this ) refers to the input with type="button" (i.e. the accept or
reject button). We need to traverse two levels up to get the div that has
an ID.

Change-Id: Iedcd1f53ed3341acf2d07d90d181587b3cbc6cbb