package/turbolua: Fix optional openssl dependency

turbolua fails to build when we have openssl selected, because it didn't
mention openssl in the dependency list.

Fix build failure by specifying openssl in dependency list when it is
selected.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>