When running answers-based automation, the SSH controller looks into
more than one section to find ssh-import-id directives.
If the "SSH" section exists, then it is where the ssh-import-id
directives must be placed. However, if the section does not exist, the
controller will also look for ssh-import-id directives in the "Identity"
section.
The answers.yaml file used this special mechanism. This is fine.
However, if one adds a SSH section to customize other settings (e.g.,
install_server, pwauth), then the ssh-import-id directives in the
Identity section suddently get ignored ; which is confusing and looks
as if there is a bug.
Let's move ssh-import-id directives to the SSH section.
Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>