use the correct url for the go example'

same here, the url is for the tickers, not the worker-pools example

Author: parasquid

examples/go-by-example-channels/worker-pools.rb

@@ -5,7 +5,7 @@
 Channel = Concurrent::Channel
 
 ## Go by Example: Go by Example: Worker Pools
-# https://gobyexample.com/tickers
+# https://gobyexample.com/worker-pools
 
 def worker(id, jobs, results)
   jobs.each do |j|