crypto: remove unnecessary template class

I came across this template class but I don't understand why it is
there. It is not used in the template specialization following it.

I just wanted to bring it up just in case this is something that
has been overlooked.

PR-URL: #12993
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

src/node_crypto.cc

@@ -155,7 +155,6 @@ std::string extra_root_certs_file;  // NOLINT(runtime/string)
 X509_STORE* root_cert_store;
 
 // Just to generate static methods
-template class SSLWrap<TLSWrap>;
 template void SSLWrap<TLSWrap>::AddMethods(Environment* env,
                                            Local<FunctionTemplate> t);
 template void SSLWrap<TLSWrap>::InitNPN(SecureContext* sc);