fix update time when session is created

src/meta/processors/session/SessionManagerProcessor.cpp

@@ -23,7 +23,7 @@ void CreateSessionProcessor::process(const cpp2::CreateSessionReq& req) {
   // The sessionId is generated by microsecond timestamp
   session.session_id_ref() = time::WallClock::fastNowInMicroSec();
   session.create_time_ref() = session.get_session_id();
-  session.update_time_ref() = 0;
+  session.update_time_ref() = session.get_create_time();
   session.user_name_ref() = user;
   session.graph_addr_ref() = req.get_graph_addr();
   session.client_ip_ref() = req.get_client_ip();