chg: forward SIGWINCH to worker

Before this patch, if the user uses chg and ncurses interface, resizing the
terminal window will mess up its content.

This patch fixes the issue by forwarding SIGWINCH to the worker process.

contrib/chg/chg.c

@@ -397,6 +397,10 b' static void setupsignalhandler(pid_t pid'
 	if (sigaction(SIGTERM, &sa, NULL) < 0)
 		goto error;
 
+	/* notify the worker about window resize events */
+	sa.sa_flags = SA_RESTART;
+	if (sigaction(SIGWINCH, &sa, NULL) < 0)
+		goto error;
 	/* propagate job control requests to worker */
 	sa.sa_handler = forwardsignal;
 	sa.sa_flags = SA_RESTART;