Fix bug with BoringSSLError.invalidSNIName exception (#702)
Fix bug with BoringSSLError.invalidSNIName exception (#702)

* Fix bug with BoringSSLError.invalidSNIName exception when host in ClientConnection is IP address

* Log message when no TLS SNI extension value set

* Improve log message shown when TLS serverHostname is skipped

grpc/grpc-swift,grpc/grpc-swift,grpc/grpc-swift,grpc/grpc-swift,grpc/grpc-swift