rapidjson: add license hash

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/rapidjson/rapidjson.hash

@@ -1,2 +1,3 @@
 # Locally calculated
 sha256 bf7ced29704a1e696fbccf2a2b4ea068e7774fa37f6d7dd4039d0787f8bed98e  rapidjson-v1.1.0.tar.gz
+sha256 a140e5d46fe734a1c78f1a3c3ef207871dd75648be71fdda8e309b23ab8b1f32  license.txt