on *:text:!vain:*:{
  if (%links == true) notice $nick Vain: http://media.putfile.com/Norther---Vain
}
// this is where your brackets were wrong above

on *:text:links*:*:{
  if ($2 == off) { 
    set %links false
    notice $nick The links is now switched OFF
  }
  if ($2 == on) { 
    set %links true
    notice $nick The links is now switched ON
  }
}
// only two brackets needed there ^