update MS4W url

Author: jmckenna

en/mapscript/php/by_example.txt

@@ -597,5 +597,5 @@ built on PHPMapScript). Goodbye, and thanks for reading this far.
 .. _`list archives`: https://lists.osgeo.org/pipermail/mapserver-users/
 .. _`mapserver-dev list`: https://lists.osgeo.org/mailman/listinfo/mapserver-dev/ 
 .. _`here`: http://dl.maptools.org/dl/
-.. _`MS4W packaged application`: http://www.ms4w.com/download.html
+.. _`MS4W packaged application`: https://ms4w.com/download.html
 .. _`MapTools site`: http://www.maptools.org/