Below are changes in the packaging method

 - Use tarball provided by the upstream project maintainer instead of
   cloning the whole git-repo
 - Drop openssl variant as it was deprecated then removed by the
   upstream project
 - Add dependency on libev, libsodium, libudns as they are not bundled
   with the source code anymore

Addresses issue #4191

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>