src: fix documentation url in help message

Refer to https://iojs.org/ for documentation

PR-URL: #378
Reviewed-By: Rod Vagg <[email protected]>

Author: Shigeki Ohtsu

src/node.cc

@@ -2911,7 +2911,7 @@ static void PrintHelp() {
 #endif
 #endif
          "\n"
-         "Documentation can be found at http://nodejs.org/\n");
+         "Documentation can be found at https://iojs.org/\n");
 }