Fix issue when no context_free_data

libraries/chain/include/eosio/chain/contracts/abi_serializer.hpp

@@ -340,10 +340,11 @@ namespace impl {
       static void extract( const variant& v, packed_transaction& ptrx, Resolver resolver ) {
          const variant_object& vo = v.get_object();
          FC_ASSERT(vo.contains("signatures"));
-         FC_ASSERT(vo.contains("context_free_data"));
          FC_ASSERT(vo.contains("compression"));
          from_variant(vo["signatures"], ptrx.signatures);
-         from_variant(vo["context_free_data"], ptrx.context_free_data);
+         if ( vo.contains("context_free_data")) {
+            from_variant(vo["context_free_data"], ptrx.context_free_data);
+         }
          from_variant(vo["compression"], ptrx.compression);
 
          if (vo.contains("hex_data") && vo["hex_data"].is_string() && !vo["hex_data"].as_string().empty()) {