[GRASS-git] [OSGeo/grass] c05ef6: change to alpine version 3.12 (#711)

[AnikaBettge]

  Branch: refs/heads/master
  Home:   https://github.com/OSGeo/grass
  Commit: c05ef6de3fcaeb73d586b99bcb29c383933e61f5
      https://github.com/OSGeo/grass/commit/c05ef6de3fcaeb73d586b99bcb29c383933e61f5
  Author: AnikaBettge <37300249+AnikaBettge at users.noreply.github.com>
  Date:   2020-06-17 (Wed, 17 Jun 2020)

  Changed paths:
    M docker/alpine/Dockerfile_alpine

  Log Message:
  -----------
  change to alpine version 3.12 (#711)