sysutils/ipfs-go downloads pre-built binaries while sources are available

[Yuri]

There should be no reason to download prebuilt executables for open 
source software. Binaries present security risk.

It violates chapter 5.4 of PHB which mentions that MASTER_SITES/DISTNAME 
refers to "source archive", and for sysutils/ipfs-go it isn't a source 
archive.


This port should be either deleted or reworked.


Yuri