This reverts commit 334f399ee3, reversing
changes made to 45a5d28bad.
When testing against Windows SSH the Powershell script fails to parse
the newly added if statement.
* Modifies the amazon-ebs builder with a windows build configuration
```
⇶ ACC_TEST_BUILDERS=amazon-ebs ACC_TEST_PROVISIONERS=powershell go test -v ./provisioner/powershell/... -run=TestPowershellProvisioner_Inline
--- PASS: TestPowershellProvisioner_Inline (256.50s)
--- PASS: TestPowershellProvisioner_Inline/testing_amazon-ebs_builder_against_powershell_provisioner (256.50s)
PASS
ok github.com/hashicorp/packer/provisioner/powershell 256.525s
```