lib/file: initialise crypto backend on open
lib/file: initialise crypto backend on open

openSSL needs to be initialised via sign_init() before processing the
publish settings file, otherwise it fails.

Signed-off-by: David Disseldorp <589a549dc9f982d9f46aeeb82a09ab6d87ccf1d8@suse.de>

ddiss/elasto,ddiss/elasto