Cantus Index Items with Error Messages as ID

Hi @dchiller and @annamorphism

While fetching Cantus Index JSON data using the list of cids available at `https://cantusindex.org/json-cids`, I noticed four chants whose CID were error messages:

`Error: Genre BD needs to be defined as a related chant. Please contact admins.` (appears twice)
`Error: Genre HV needs to be defined as a related chant. Please contact admins.`
`Error: Please delete this chant or contact admins`

Despite that, I was able to retrieve their JSON records at https://cantusindex.org/json-cid-data/{cid}

Two of these chants can also be found through the Cantus Index webpage:
`https://cantusindex.org/node/156455`
`https://cantusindex.org/node/156454`

Is this expected behavior?