[btcsuite/btcd] efb4ab: main: Improve comment for headers peer message.

[Alex Bosworth]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcd
  Commit: efb4ab430c895b808357c387f336060cf9f1abc2
      
https://github.com/btcsuite/btcd/commit/efb4ab430c895b808357c387f336060cf9f1abc2
  Author: Alex Bosworth <alexboswo...@users.noreply.github.com>
  Date:   2017-03-22 (Wed, 22 Mar 2017)

  Changed paths:
    M blockmanager.go

  Log Message:
  -----------
  main: Improve comment for headers peer message.