fix Makefile chmod (644)
replace MD5SUM with HASH
add PKG_MIRROR_HASH when PKG_SOURCE_PROTO:=git

(PKG_SOURCE_PROTO:=svn tarballs are not reproducible for now)

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

nDPI is an open source LGPLv3 library for deep-packet inspection. Based
on OpenDPI it includes ntop extensions. It had been tried to push the
source code into the OpenDPI source tree but nobody answered emails
so the ntop team had decided to create their own source tree.

github site: https://github.com/ntop/nDPI
official site: http://www.ntop.org/

Signed-off-by: BangLang Huang <banglang.huang@foxmail.com>