[watchmedo] Exit gracefully on KeyboardInterrupt Exception (Ctrl+C)

[cernekj]

This change solves response of watchmedo on user's command termination from terminal using Ctrl+C keystroke.
Before:

$ /Users/user1/Library/Python/3.9/bin/watchmedo shell-command
^CTraceback (most recent call last):
  File "/Users/user1/Library/Python/3.9/bin/watchmedo", line 8, in <module>
    sys.exit(main())
  File "/Users/user1/Library/Python/3.9/lib/python/site-packages/watchdog/watchmedo.py", line 675, in main
    args.func(args)
  File "/Users/user1/Library/Python/3.9/lib/python/site-packages/watchdog/watchmedo.py", line 526, in shell_command
    observe_with(observer, handler, args.directories, args.recursive)
  File "/Users/user1/Library/Python/3.9/lib/python/site-packages/watchdog/watchmedo.py", line 183, in observe_with
    time.sleep(1)
KeyboardInterrupt

After proposed change:

$ /Users/user1/Library/Python/3.9/bin/watchmedo shell-command
^C

Returns exit status code No. 130

[BoboTiG]

Thanks @cernekj !

Do you mind adding a line, and your GitHub nickname, in the changelog 🙏 ?

[cernekj]

Hi @BoboTiG , thank you for opportunity to choose if I want to :-)
I don't think it it necessary, but if you prefer it, then feel free to do so.