无法在Jenkins中下载GitHub插件

我无法从Jenkins下载GitHub插件。下面是我的代理配置

我得到以下错误：

 Failure -
 java.io.IOException: Failed to dynamically deploy this plugin
  at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1317)
  at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1116)
   at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
 at java.util.concurrent.FutureTask.run(Unknown Source)
 at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:104)
at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: Failed to install github plugin
at hudson.PluginManager.dynamicLoad(PluginManager.java:450)
at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1313)
... 5 more
Caused by: java.io.IOException: Dependency ssh-agent (1.3), github-api (1.42), git (2.0), git-client (1.4.4), scm-api (0.1) doesn't exist
at hudson.PluginWrapper.resolvePluginDependencies(PluginWrapper.java:488)
at hudson.PluginManager.dynamicLoad(PluginManager.java:440)
... 6 more

它告诉你：

原因：java.io.IOException:依赖ssh代理（1.3）、github api（1.42）、git（2.0）、git客户端（1.4.4）、scm api（0.1）不存在

首先尝试下载这些其他提到的依赖项（尽管它们应该是自动安装的）