package/snmppp: requires DES support in openssl

Enable DES in openssl to fix build failure raised since commit
a83d41867c8d69a77d5cd0a665aa216af5340359

Fixes:
 - http://autobuild.buildroot.org/results/2aece7e503d36ebee2bce526f11b2400b9df761e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/snmppp/Config.in

@@ -23,6 +23,7 @@ config BR2_PACKAGE_SNMPPP_SNMPV3
 	default y
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 # C++11
 	select BR2_PACKAGE_OPENSSL
+	select BR2_PACKAGE_LIBOPENSSL_ENABLE_DES if BR2_PACKAGE_LIBOPENSSL
 	help
 	  Enable optional support for SNMP++. This selects OpenSSL.