[GRASS-git] [OSGeo/grass] 509d0a: use proj 6.2.1 in Alpine Dockerfile (#255)

[mmacata]

  Branch: refs/heads/releasebranch_7_8
  Home:   https://github.com/OSGeo/grass
  Commit: 509d0afb4948ea171c79a15ddcdf647567963dc5
      https://github.com/OSGeo/grass/commit/509d0afb4948ea171c79a15ddcdf647567963dc5
  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