#20 optionally, load private keys from same file as certificates

[Martin Peylo]

Like apparently possible in apps/s_server.c:

758 {"key", OPT_KEY, '<',
759 "Private Key if not in -cert; default is " TEST_CERT},

[David von Oheimb]

This is already possible (and in a cleaner way than for s_server) by specifying the same PEM or PKCS#12 file for key and cert.