Update consecutive.cpp

Write a C++ program that continuously reads integers from the console input (cin) until

four consecutive integers are found, or
the end-of-file is encountered
If four consecutive integers are found, the program should print them, as follows:

Quadruplet found: 15 16 17 18
and then quit.

If no quadruplet is found, the program should exit silently (i.e. print nothing).