title: TeamCity + git and authentication for submodules
body: <p>Trying to configure TeamCity to build our project, I'm having trouble getting the git VCS module to checkout a submodule. The submodule should be checked out using the same authentication as the root module, but I cannot figure out how to configure TeamCity for this. I have tried both password and private key authentication, but they both fail:</p>
  
  <pre><code>[12:07:14]: Patch is broken, can be found in file: C:\TeamCity\buildAgent\temp\cache\temp8149231956777659708patch_48
  [12:07:14]: RunBuildException when running build stage UpdateSourcesFromServer: Failed to build patch for build 31 {build id=48}, VCS root: ssh://host/repo#master {id=2}, due to error: Patch building failed: 
  jetbrains.buildServer.buildTriggers.vcs.git.submodules.SubmoduleFetchException: Cannot fetch submodule. Repository URL: 'ssh://*****@host/repo', submodule path: 'subrepo'.
  org.eclipse.jgit.errors.TransportException: ssh://*****@host/subrepo: Auth fail
  com.jcraft.jsch.JSchException: Auth fail
  </code></pre>
  
  <p>TeamCity runs on a windows machine and the git repos are on a linux machine.</p>
  
  <p>Is it possible to configure authentication for submodules in TeamCity, or can anyone come up with a good workaround?</p>