Clean up http.ListenAndServe

[thinkverse]

This PR cleans up the http.ListenAndServe if statement by removing the redundant Sprintf call, it's already available from earlier in main. So no need to duplicate it again.

sample-golang/main.go

Line 121 in 0033b3f

bindAddr := fmt.Sprintf(":%s", port)

Also simplified the if statement more by taking advantage of Go's ability to initialize local variables inside if statements.