package/stunnel: requires DES support in openssl
Enable DES in openssl to fix build failure raised since commit
a83d41867c8d69a77d5cd0a665aa216af5340359
Fixes:
- http://autobuild.buildroot.org/results/4b306a13f543bbabf3f01d882b3549e3d9961556
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>