Why $me = %botnick? I don't think it's needed unless you want your bot to be that of a certain nickname...

You only need one check for ops, rather than using two operators. An if and then else condition will do the trick.

You can do these in a couple of ways:

on *:TEXT:!topic*:#: {
  if ($nick isop $chan) {
    topic # $$2-
  }
  else {
    notice $nick You aren't an op. No topic for you.
  }
}

Or:

on *:TEXT:!topic *:#: {
  if ($nick !isop #) { 
  notice $nick You aren't an op. No topic for you. 
 }
  else { 
   topic # $2- 
  }
}

Or:

on *:TEXT:!topic *:#: { 
$iif($nick !isop #,notice $nick You aren't an op. No topic for you.,topic # $2-) 
}

I'll recommend you add a flood protection to this, in case somebody tampers with the code by way of trigger flood. For instance:

on *:TEXT:!topic*:#: {
 if (!%f) {
   inc -u5 %f
  if ($nick isop $chan) {
    topic # $$2-
  }
  else {
    notice $nick You aren't an op. No topic for you.
  }
 }
}