MINOR: hlua: Be able to disable logging from lua

Add core.silent (-1) value to be able to disable logging via
TXN:set_loglevel() call. Otherwise, there is no way to do so and it may be
handy. This special value cannot be used with TXN:log() function.

This patch may be backported if necessary.

(cherry picked from commit 31ec9f18bb73737fc8e96f8781e1f251ddc44522)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 65f5395d76a4745d985174b23f3c8c53fd5c56ea)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
2 files changed