[kronolith] Horde/Kronolith should support X-Forwarded-Proto or Forwarded

[Ob Noxious]

Hi,

I know, this is not directly a Kronolight matter but I'm only on this list
:-)

The framework should support "X-Forwarded-Proto" HTTP header when using
"$conf['use_ssl'] = 2" (auto-detect).

Currently, it does not. I had to force "$conf['use_ssl'] = 1" to make it
work correctly.

Maybe add a "$conf['use_ssl'] = 3" to auto-detect via headers and check
"X-Forwarded-Proto: https"

What do you think?

-- 
ObNox