Use JSON for DeepL API requests

Signed-off-by: nicole mikołajczyk <git@mkljczk.pl>

changelog.d/deepl-json.fix

@@ -0,0 +1 @@
+Use JSON for DeepL API requests

lib/pleroma/language/translation/deepl.ex

@@ -24,17 +24,15 @@ defmodule Pleroma.Language.Translation.Deepl do
       |> URI.to_string()
 
     case Pleroma.HTTP.post(
-           endpoint <>
-             "?" <>
-             URI.encode_query(%{
-               text: content,
+           endpoint,
+           Jason.encode!(%{
+             text: [content],
              source_lang: source_language |> String.upcase(),
              target_lang: target_language,
              tag_handling: "html"
            }),
-           "",
            [
-             {"Content-Type", "application/x-www-form-urlencoded"},
+             {"Content-Type", "application/json"},
              {"Authorization", "DeepL-Auth-Key #{api_key()}"}
            ]
          ) do