Fix the example for terraform saml connector

[PLJanicki]

teleport-plugins/terraform/example/saml_connector.tf.example

Lines 29 to 39 in cd35664

	attributes_to_roles = [{
	name = "groups"
	roles = ["example"]
	value = "okta-admin"
	}]
	attributes_to_roles = [{
	name = "groups"
	roles = ["example"]
	value = "okta-dev"
	}]

attributes_to_roles is a set so it should look like this:

attributes_to_roles = [
{
    name  = "groups"
    roles = ["role1", "role2"] 
    value = "okta-admin"
  },
  {
    name  = "groups"
    roles = ["role3", "role4"] 
    value = "okta-dev"
  }
]