Initial DNS Seedlist Discovery Spec:

If any connection string option in a TXT record is incorrectly formatted, a Client must throw a parse exception.

In our first implementation in 1.9.0, an incorrectly formatted option only results in a warning; it should be an error. Distinguishing between fatal errors and warnings in mongoc_uri_parse_options requires more work than we have time for in this release.

Copy txt-record-wrong-value-type.json from the specs repo to test.