Make attachment links configurable

Thanks @href!

docs/config.md

@@ -95,6 +95,7 @@ config :pleroma, Pleroma.Mailer,
     older software for theses nicknames.
 * `max_pinned_statuses`: The maximum number of pinned statuses. `0` will disable the feature.
 * `autofollowed_nicknames`: Set to nicknames of (local) users that every new user should automatically follow.
+* `no_attachment_links`: Set to true to disable automatically adding attachment link text to statuses
 
 ## :logger
 * `backends`: `:console` is used to send logs to stdout, `{ExSyslogger, :ex_syslogger}` to log to syslog

lib/pleroma/web/common_api/common_api.ex

@@ -103,7 +103,7 @@ def post(user, %{"status" => status} = data) do
              attachments,
              tags,
              get_content_type(data["content_type"]),
-             Enum.member?([true, "true"], data["no_attachment_links"])
+             Enum.member?([true, "true"], Map.get(data, "no_attachment_links", Pleroma.Config.get([:instance, :no_attachment_links], true)))
            ),
          context <- make_context(inReplyTo),
          cw <- data["spoiler_text"],

lib/pleroma/web/mastodon_api/mastodon_api_controller.ex

@@ -341,7 +341,6 @@ def post_status(%{assigns: %{user: user}} = conn, %{"status" => _} = params) do
     params =
       params
       |> Map.put("in_reply_to_status_id", params["in_reply_to_id"])
-      |> Map.put("no_attachment_links", true)
 
     idempotency_key =
       case get_req_header(conn, "idempotency-key") do