Backport OpenSSL commit af58be768ebb690f78530f796e92b8ae5c9a4401:

Backport OpenSSL commit af58be768ebb690f78530f796e92b8ae5c9a4401:

  Don't allow too many consecutive warning alerts

  Certain warning alerts are ignored if they are received. This can mean that
  no progress will be made if one peer continually sends those warning alerts.
  Implement a count so that we abort the connection if we receive too many.

  Issue reported by Shi Lei.

This is a direct commit to stable/10 and stable/9.

Security:	CVE-2016-8610

git-svn-id: svn://svn.freebsd.org/base/stable/10@308200 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f