Bug 1012666 - Fix up checking if IRC topics are settable: fix typo causing bustage. r=clokep a=DONTBUILD chat-only regression fix on CLOSED TREE

chat/protocols/irc/irc.js

@@ -540,7 +540,7 @@ ircChannel.prototype = {
   },
   get topicSettable() {
     // We must be in the room to set the topic.
-    if (!this.left)
+    if (this.left)
       return false;
 
     // If the channel mode is +t, hops and ops can set the topic; otherwise