Though the TLSWrap constructor is only called via TLSWrap::Wrap() (i.e.
tls_wrap.wrap()) internally, it is still exposed to JS. Don't allow the
application to abort by inspecting the instance before it has been
wrap'd by another handle.
PR-URL: https://github.com/nodejs/node/pull/6184
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
