[bug] object does not have an attribute named "global_settings_key"

[nusrath432]

object does not have an attribute named "global_settings_key"
This bug is introduced by the commit 4c2da76

To Reproduce
To reproduce define a landingzone.tfvars without global_settings_key = "" especially this key is not required when we are not using any global_settings or prefixes from other landingzone i.e using custom_variables = {} block instead of global_settings = {} block.

Expected behavior
If not defined, it should ignore.
try(data.terraform_remote_state.remote[var.landingzone.global_settings_key].outputs.tfstates, {})