title: Xcode 7 GM can not authenticate git repository
body: <p>I could commit to this repository without problem with Xcode 6. git still works fine in terminal, i can commit both locally and to the remote. In Xcode 7, I can commit locally but not remotely. it says authentication fails and it is impossible to reset the username. (it's greyed out). I have the proper username in my local git config file. I've also tried to create a new account but I end up with the same problem of not being able to enter the userName.</p>
  
  <p>my  git config --local --list</p>
  
  <pre><code>core.repositoryformatversion=0
  core.filemode=true
  core.bare=false
  core.logallrefupdates=true
  core.ignorecase=true
  core.precomposeunicode=true
  remote.origin.url=git@bitbucket.org:myUserName/myProject.git
  remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
  branch.failedTryToRename.remote=origin
  branch.failedTryToRename.merge=refs/heads/master
  branch.master.remote=origin
  branch.master.merge=refs/heads/master
  branch.master1.remote=origin
  branch.master1.merge=refs/heads/master
  user.name=myUserName
  user.email=myUserName@gmail.com
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/wZbXr.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wZbXr.jpg" alt="XcodeAccountsScreen"></a></p>