MM-22049: Add idle timeout to the HTTP server (#13788)

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/server.go

@@ -515,6 +515,7 @@ func (s *Server) Start() error {
 		Handler:      handler,
 		ReadTimeout:  time.Duration(*s.Config().ServiceSettings.ReadTimeout) * time.Second,
 		WriteTimeout: time.Duration(*s.Config().ServiceSettings.WriteTimeout) * time.Second,
+		IdleTimeout:  time.Duration(*s.Config().ServiceSettings.IdleTimeout) * time.Second,
 		ErrorLog:     errStdLog,
 	}