fix: Sync Users loop stops when there is a deleted user

[jverhoeks]

*Issue #10

Description of changes:
When there are deleted users in Gsuite that are previous synced to AWS SSO the logic stops the whole syncUsers loop

The current loop is:

uu, err := s.aws.FindUserByEmail(u.PrimaryEmail)
if err != aws.ErrUserNotFound  {

However aws.FindUserByEmail
return aws.ErrUserNotFound when a user is not found and nil when a user is found.

Replaced with:

if err != aws.ErrUserNotFound && err != nil {

and added extra logging around deleting users.

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[katallaxie]

Left a minor comment.

[katallaxie]

Let's make this simpler. if uu == nil { return err }. it should always be nil when there is and error.

[jverhoeks]

I think not.
For the following use-case
deleted_users = [userA@domain.com, userB@domain.com]
where UserA is doesn't exist but userB yes on SSO

FinduserByEmail (userA)

• err = aws.ErrUserNotFound
• uu = nil
  action -> continue
  go to the next user in the list

FinduserByEmail (userB)

• err = nil
• uu = object
  action
  -> DeleteUser
  go to the next user in the list

if uu == nil and the error is different , then the function should break the whole loop and return err as there is an unexpected errror