tls: tls_wrap causes debug assert in vector

When using a debug build (on Windows specifically) the error case for
tls_wrap causes an assert to fire because the index being passed is
outside the bounds of the vector.

The fix is to switch to iterators.

PR-URL: https://github.com/nodejs/node/pull/18830


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>