[package] lighttpd: configure with OpenSSL support only if the user asks for it

[package] lighttpd: configure with OpenSSL support only if the user asks for it

SSL support adds a quite large dependency to lighttpd when compiled
in. On a 32 bit platform, libcrypto is roughly 1MB, to which one must
add the size of libssl (roughly 250KB). This is 2 to 5 times the size
of a typical lighttpd embedded installation.

SSL support is only needed if one enables the SSL engine in the
lighttpd.conf configuration file.

This patch introduces a configuration option that allows the user to
choose whether or not he wants to compile SSL support in. It defaults
to 'y' only if libopenssl is already selected (either by active
selection or because libopenssl is a dependency of another package).

Signed-off-by: Emmanuel Deloget <logout@free.fr>
git-svn-id: svn://svn.openwrt.org/openwrt/packages@31097 3c298f89-4303-0410-b956-a3cf2f4a3e73