Update 15.1.md (#509)

fix some bug

eBook/15.1.md

@@ -83,8 +83,8 @@ func main() {
 		fmt.Println("What to send to the server? Type Q to quit.")
 		input, _ := inputReader.ReadString('\n')
 		trimmedInput := strings.Trim(input, "\r\n")
-		// fmt.Printf("input:--s%--", input)
-		// fmt.Printf("trimmedInput:--s%--", trimmedInput)
+		// fmt.Printf("input:--%s--", input)
+		// fmt.Printf("trimmedInput:--%s--", trimmedInput)
 		if trimmedInput == "Q" {
 			return
 		}