Added migration for setting default tags in existing users records

priv/repo/migrations/20190301101154_add_default_tags_to_user.exs

@@ -0,0 +1,9 @@
+defmodule Pleroma.Repo.Migrations.AddDefaultTagsToUser do
+  use Ecto.Migration
+
+  def up do
+    execute "UPDATE users SET tags = array[]::varchar[] where tags IS NULL"
+  end
+
+  def down, do: :noop
+end