title: "log out" from old github account and use other one for smartgit
body: <p>For some obscure reason it doesnt seem straightforward to change of account in smartgit:
  I had an old account that I would like not to use to commit things in another repo. Despite removing everything in Edit->Preferences->Authentification Smartgit is still not asking me for new credentials ... I don't know what I am missing here</p>