src: added newline in help message

PR-URL: https://github.com/nodejs/node/pull/13315
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node.cc

@@ -3632,7 +3632,7 @@ static void PrintHelp() {
          "  -r, --require              module to preload (option can be "
          "repeated)\n"
          "  -                          script read from stdin (default; "
-         "interactive mode if a tty)"
+         "interactive mode if a tty)\n"
 #if HAVE_INSPECTOR
          "  --inspect[=[host:]port]    activate inspector on host:port\n"
          "                             (default: 127.0.0.1:9229)\n"