title: git message "load pubkey ... invalid format" after upgrade to Git 2.27
body: <p>After upgrading to <strong>Git 2.27</strong> (on Windows) whenever I execute operations on remote repositories authorized with SSH, Git emits <em>&quot;load pubkey ... invalid format&quot;</em> claiming that the private key file has an invalid format. The operation is executed successfully anyway but message is strange.</p>
  <p>Checked file format (UTF) and LF line endings, copied private key file from an unmodified source to <code>.ssh</code> folder. No success.</p>