backport patch for backtrace detection in h2o.

This patch solves the issue of uclibc pretending to be glibc

Signed-off-by: James Taylor <james@jtaylor.id.au>

Update wslay link patch with upstream fix from h2o/h2o#2196

Signed-off-by: James Taylor <james@jtaylor.id.au>

H2O is a new generation HTTP server that provides quicker response to users
  with less CPU utilization when compared to older generation of web servers.
  Designed from ground-up, the server takes full advantage of HTTP/2 features
  including prioritized content serving and server push, promising outstanding
  experience to the visitors of your web site.

Signed-off-by: James Taylor <james@jtaylor.id.au>