Change type of RemoteCertificate property in TlsHandler to X509Certificate2 (#231)
Change type of RemoteCertificate property in TlsHandler to X509Certificate2 (#231)

* Change type of RemoteCertificate property in TlsHandler to X509Certificate2

* Add null check for RemoteCertificate

* Address comments

krish-gh/DotNetty,hide1202/DotNetty,krish-gh/DotNetty,hide1202/DotNetty