Qnx: Fixing incorrect ssh key generation

blackberry-connect tool requires to have public key with no comment
or comment with 'usename@hostname' format
QSsh::SshKeyGenerator creates comments in 'QtCreator/TIMEZONE' format
there we are stripping them out

This issue has been introduced by commit:
bd064d50

Task-number: QTCREATORBUG-9888

Change-Id: Ied96720b004cfe4f5bb95adec3401b6b6d30db5c
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>