fix: incorrect mapper upload engines api

Author: luke-nguyen990

engine/controllers/engines.cc

@@ -278,6 +278,7 @@ void Engines::UnloadEngine(
     const HttpRequestPtr& req,
     std::function<void(const HttpResponsePtr&)>&& callback,
     const std::string& engine) {
+  std::cout << "Unload engine: " << engine << std::endl;
   auto result = engine_service_->UnloadEngine(engine);
   if (result.has_error()) {
     Json::Value res;

engine/controllers/engines.h

@@ -42,7 +42,7 @@ class Engines : public drogon::HttpController<Engines, false> {
                 Get);
 
   ADD_METHOD_TO(Engines::LoadEngine, "/v1/engines/{1}/load", Options, Post);
-  ADD_METHOD_TO(Engines::UnloadEngine, "/v1/engines/{1}/load", Options, Post);
+  ADD_METHOD_TO(Engines::UnloadEngine, "/v1/engines/{1}/load", Options, Delete);
   ADD_METHOD_TO(Engines::UpdateEngine, "/v1/engines/{1}/update", Options, Post);
   ADD_METHOD_TO(Engines::GetEngineVersions, "/v1/engines/{1}/versions", Get);
   ADD_METHOD_TO(Engines::GetEngineVariants, "/v1/engines/{1}/versions/{2}",