tls: nullify `.ssl` on handle close
This is an intermediate fix for an issue of accessing TLSWrap
fields
after the parent handle was destroyed. While close
listener cleans up
this field automatically, it can be done even earlier at the
TLSWrap.close
call.
Proper fix is going to be submitted and landed after this one.
Fix: #5108 (closed)
R = @bnoordhuis or @shigeki
cc @nodejs/crypto