Update collatzcountdown.en.md

subjects/collatzcountdown.en.md

@@ -33,15 +33,8 @@ func main() {
 And its output :
 
 ```console
-<<<<<<< HEAD
-student@ubuntu:~/student/test$ go build
-student@ubuntu:~/student/test$ ./test
-10
-student@ubuntu:~/student/test$
-=======
 student@ubuntu:~/piscine/test$ go build
 student@ubuntu:~/piscine/test$ ./test
 10
 student@ubuntu:~/piscine/test$
->>>>>>> 3fe258c999f5918c6b750a6cbe511a7874883d25
 ```