Revert "freebsd: try using wait_to_add_keys"

This reverts commit 6eaa9b56018305d75d11d96388a74f0faa9f71a0.

Reason for revert: didn't work.  Is no longer a supported option in packer.

Change-Id: I77dd78e60c1208b914523dc97e0aef998356233a
diff --git a/packer_freebsd.json b/packer_freebsd.json
index 9ab6213..ecc6724 100644
--- a/packer_freebsd.json
+++ b/packer_freebsd.json
@@ -7,7 +7,6 @@
     {
       "type": "amazon-ebs",
       "name": "freebsd-12.3-mbedtls",
-      "wait_to_add_ssh_keys": "20s",
       "vpc_id":  "vpc-d28c0ca9",
       "subnet_id": "subnet-a0d573af ",
       "region": "{{user `vpc_region`}}",