Revert "Podman compatibility"

This reverts commit 0030222.

Author: rnc

docker_squash/v2_image.py

@@ -16,9 +16,6 @@ class V2Image(Image):
     def _before_squashing(self):
         super(V2Image, self)._before_squashing()
 
-        # New OCI Archive format type
-        self.oci_format = True
-
         # Read old image manifest file
         self.old_image_manifest = self._get_manifest()
         self.log.debug(
@@ -378,6 +375,8 @@ def _generate_image_metadata(self):
 
     def _get_manifest(self):
         if os.path.exists(os.path.join(self.old_image_dir, "index.json")):
+            # New OCI Archive format type
+            self.oci_format = True
             # Not using index.json to extract manifest details as while the config
             # sha could be extracted via some indirection i.e.
             #