Use fast DH params when creating certs

Otherwise installation on low power systems takes way too long

src/freedombone-addcert

 # generate DH params
 if [ ! $NODH ]; then
     if [ ! -f /etc/ssl/certs/${CERTFILE}.dhparam ]; then
-        ${PROJECT_NAME}-dhparam -h ${CERTFILE}
+        ${PROJECT_NAME}-dhparam -h ${CERTFILE} --fast yes
     fi
 fi