fix for migrate task

lib/mix/tasks/pleroma/config.ex

@@ -45,7 +45,7 @@ def run(["migrate_from_db", env, delete?]) do
     if Pleroma.Config.get([:instance, :dynamic_configuration]) do
       config_path = "config/#{env}.exported_from_db.secret.exs"
 
-      {:ok, file} = File.open(config_path, [:write])
+      {:ok, file} = File.open(config_path, [:write, :utf8])
       IO.write(file, "use Mix.Config\r\n")
 
       Repo.all(Config)

lib/pleroma/docs/json.ex

@@ -5,7 +5,7 @@ defmodule Pleroma.Docs.JSON do
   def process(descriptions) do
     config_path = "docs/generate_config.json"
 
-    with {:ok, file} <- File.open(config_path, [:write]),
+    with {:ok, file} <- File.open(config_path, [:write, :utf8]),
          json <- generate_json(descriptions),
          :ok <- IO.write(file, json),
          :ok <- File.close(file) do

test/web/admin_api/admin_api_controller_test.exs

@@ -2269,6 +2269,10 @@ test "delete part of settings by atom subkeys", %{conn: conn} do
       Pleroma.Config.put([:instance, :dynamic_configuration], true)
     end
 
+    clear_config([:feed, :post_title]) do
+      Pleroma.Config.put([:feed, :post_title], %{max_length: 100, omission: "…"})
+    end
+
     test "transfer settings to DB and to file", %{conn: conn, admin: admin} do
       assert Pleroma.Repo.all(Pleroma.Web.AdminAPI.Config) == []
       conn = get(conn, "/api/pleroma/admin/config/migrate_to_db")