Since migrating to libmongoc streams in PHPC-605, we can no longer override the server's host name (it was only supported on PHP streams). The certificates will need to be recreated.
IIRC, bjori also said we should be able to use Subject Alternative Name (SAN) for this.
Update PHP driver to test in Evergreen
Fix peer certificate verification errors for SSL clusters
Regenerate test certificates with SHA256 signatures