Merge branch 'backport/1.0-index-fix' into 'master'

Backport like index fix to 1.0

See merge request pleroma/pleroma!1740

priv/repo/migrations/20190823000549_add_likes_index_to_objects.exs

@@ -0,0 +1,7 @@
+defmodule Pleroma.Repo.Migrations.AddLikesIndexToObjects do
+  use Ecto.Migration
+
+  def change do
+    create_if_not_exists index(:objects, ["(data->'likes')"], using: :gin, name: :objects_likes)
+  end
+end