[GRASS-git] [OSGeo/grass] 701442: use proj 6.2.1 in Alpine Dockerfile (#255)

[mmacata]

  Branch: refs/heads/master
  Home:   https://github.com/OSGeo/grass
  Commit: 70144234a034606ccfa95ed5cd8c97cc491763e4
      https://github.com/OSGeo/grass/commit/70144234a034606ccfa95ed5cd8c97cc491763e4
  Author: mmacata <mmacata at users.noreply.github.com>
  Date:   2019-12-13 (Fri, 13 Dec 2019)

  Changed paths:
    M docker/alpine/Dockerfile_alpine

  Log Message:
  -----------
  use proj 6.2.1 in Alpine Dockerfile (#255)

- switch to current and official PROJ package as offered by Alpine