Re-add exit() into exitprg()

We'll need to fix this in ciolib.

src/syncdraw/options.c

@@ -393,5 +393,6 @@ exitprg(void)
 		clrscr();
 		gotoxy(1, 1);
 		printf("Thanx 4 using this syncdraw\n");
+		exit(0);
 	}
 }