rapidjson: update site URL in package description

Signed-off-by: Danomi Manchego <danomimanchego123@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/rapidjson/Config.in

@@ -3,4 +3,4 @@ config BR2_PACKAGE_RAPIDJSON
 	help
 	  A fast JSON parser/generator for C++ with both SAX/DOM style API.
 
-	  https://code.google.com/p/rapidjson/
+	  http://rapidjson.org/