Update boost.mk

new download location for boost sources. 
patch from: https://github.com/crackfoo/but/tree/patch-1
pull request not yert merged with downstream: Butkoin#6

Author: verycoin

depends/packages/boost.mk

@@ -1,6 +1,6 @@
 package=boost
 $(package)_version=1_64_0
-$(package)_download_path=https://dl.bintray.com/boostorg/release/1.64.0/source/
+$(package)_download_path=https://boostorg.jfrog.io/artifactory/main/release/1.64.0/source/
 $(package)_file_name=$(package)_$($(package)_version).tar.bz2
 $(package)_sha256_hash=7bcc5caace97baa948931d712ea5f37038dbb1c5d89b43ad4def4ed7cb683332