Upgrades, fix astute keys migration

In some cases ssh keys copying fails
* user installs env and doesn't run
  deployment
* he runs upgrade
* it fails
* users runs it again
* it cannot copy keys and fails

The reason is, upgrade script had
a condition which reraised the
exception if directory existed.

As result we create empty directory
if there was an error.

Closes-bug: #1361284
Change-Id: Id30bc3bd8628cf6d6747c52a210f7abe9b94ca99