bugfix: updating parsing of terraform registry

[oraab]

Updating the parsing of Terraform registry (https://releases.hashicorp.com/terraform) to take care of this error:

ERROR[2022-06-19T18:25:04+03:00]/home/runner/work/simple-tfswitch/simple-tfswitch/pkg/list_versions.go:45 github.com/terraform-tools/simple-tfswitch/pkg.GetTFList() Cannot get list from mirror: https://releases.hashicorp.com/terraform
ERROR[2022-06-19T18:25:04+03:00]/home/runner/work/simple-tfswitch/simple-tfswitch/pkg/install.go:192 github.com/terraform-tools/simple-tfswitch/pkg.installFromConstraint() No version found to match constraint. Follow the README.md instructions for setup. https://github.com/terraform-tools/simple-tfswitch/blob/main/README.md

tested locally by creating build and running it on Terraform code of another repository.

[jb-abbadie]

LGTM