n-api: use Maybe version of Object::SetPrototype()

Fixes the following deprecation warning:

    ../src/node_api.cc:2020:30: warning: 'bool
    v8::Object::SetPrototype(v8::Local<v8::Value>)' is deprecated: Use
    maybe version [-Wdeprecated-declarations]
       wrapper->SetPrototype(proto);
    ../src/node_api.cc:2021:28: warning: 'bool
    v8::Object::SetPrototype(v8::Local<v8::Value>)' is deprecated: Use
    maybe version [-Wdeprecated-declarations]
       obj->SetPrototype(wrapper);

PR-URL: nodejs#14053
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

src/node_api.cc

@@ -2020,8 +2020,8 @@ napi_status napi_wrap(napi_env env,
 
   // Insert the wrapper into the object's prototype chain.
   v8::Local<v8::Value> proto = obj->GetPrototype();
-  wrapper->SetPrototype(proto);
-  obj->SetPrototype(wrapper);
+  CHECK(wrapper->SetPrototype(context, proto).FromJust());
+  CHECK(obj->SetPrototype(context, wrapper).FromJust());
 
   if (result != nullptr) {
     // The returned reference should be deleted via napi_delete_reference()