Also remove a staging-to-sync fallback (introduced in #2487588: Move CMI import/export directory "staging" to "sync", as it is confused with staging environments ) from config_get_config_directory().
Leksat created an issue. See original summary.
Duplicate of #2716163: [meta] Remove all the deprecations.
Actually we should trigger_error('...', E_USER_DEPRECATED) in the fallback code during 8.x, so re-titling and moving back for that.
Drupal 8.3.0-alpha1 will be released the week of January 30, 2017, which means new developments and disruptive changes should now be targeted against the 8.4.x-dev branch. For more information see the Drupal 8 minor version schedule and the Allowed changes during the Drupal 8 release cycle.
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