test: remove obsolete TLS test
The test involving melissadata.net was to make sure Node.js still tolerated ValiCert 1024-bit certs. It has been several years since melissadata.net used ValiCert as a root certificate and for that matter, we removed ValiCert in a4dbf45b so it would have broken then if it was still using it. The test is no longer valid or needed and hasn't been for several years.