Language client: corrected default workspace/configuration response

src/source_language_protocol.cpp

@@ -693,7 +693,7 @@ void LanguageProtocol::Client::handle_server_request(const boost::variant<size_t
     if(!settings_path.empty())
       write_response(id, filesystem::read(settings_path));
     else
-      write_response(id, "{}");
+      write_response(id, "[]");
   }
   else
     write_response(id, "{}"); // TODO: write error instead on unsupported methods