Fix a comment referring to previous (never committed) implementation

ircbot.js

@@ -43,7 +43,7 @@ function cachedCompile(program, enableExtensions = true) {
 		let {compiled, extensions} = programCache.get(program);
 
 		// If extensions enabled state is the same as ours, we can
-		// just update the useOrder and return this
+		// just return this
 		// If not, we need to compile a new program
 		if(extensions == enableExtensions) {
 			return compiled;