Revert "Merge branch 'issue/1276' into 'develop'"

This reverts merge request !1877

priv/repo/migrations/20200210050658_update_markers.exs

@@ -1,39 +0,0 @@
-defmodule Pleroma.Repo.Migrations.UpdateMarkers do
-  use Ecto.Migration
-  import Ecto.Query
-  alias Pleroma.Repo
-
-  def up do
-    update_markers()
-  end
-
-  def down do
-    :ok
-  end
-
-  defp update_markers do
-    now = NaiveDateTime.utc_now()
-
-    markers_attrs =
-      from(q in "notifications",
-        select: %{
-          timeline: "notifications",
-          user_id: q.user_id,
-          last_read_id:
-            type(fragment("MAX( CASE WHEN seen = true THEN id ELSE null END )"), :string)
-        },
-        group_by: [q.user_id]
-      )
-      |> Repo.all()
-      |> Enum.map(fn attrs ->
-        attrs
-        |> Map.put_new(:inserted_at, now)
-        |> Map.put_new(:updated_at, now)
-      end)
-
-    Repo.insert_all("markers", markers_attrs,
-      on_conflict: {:replace, [:last_read_id, :unread_count]},
-      conflict_target: [:user_id, :timeline]
-    )
-  end
-end