Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description
When /images/search fails, the respons also contains null (as no images found), however the reply is then not a valid JSON and is difficult to parse. Since code 200 means that the request succeeded, there is no need to try to show that there are not images.

Steps to reproduce the issue:

1.sudo curl --unix-socket /run/podman/podman.sock http://d/v1.24/libpod/images/search?term=fed%3A

Describe the results you received:

{"cause":"invalid reference format","message":"error getting registry from \"fed:\": invalid reference format","response":500}
null

Describe the results you expected:

{"cause":"invalid reference format","message":"error getting registry from \"fed:\": invalid reference format","response":500}

Using my own local build of current upstream.