Federator doesn't work with multiple roles if account map not configured

[SipSeb]

I recently switched from a really old build to a new one because of an architecture change. The old build was from before the account_map feature was added. After the update, federator worked as long as I don't have more than one role in AWS.

The code works only if the account_map section is present in the ini file. The else part is broken.

Pull request https://github.com/aidan-/aws-cli-federator/pull/7 fixes the behavior.