Fix the confusingly named and inverted logic of "no_attachment_links"

The setting is now simply "attachment_links" and the boolean value does
what you expect. A double negative is never possible and describing the
functionality is no longer a philospher's worst nightmare.

test/web/common_api/common_api_utils_test.exs

@@ -575,11 +575,11 @@ defmodule Pleroma.Web.CommonAPI.UtilsTest do
   end
 
   describe "maybe_add_attachments/3" do
-    test "returns parsed results when no_links is true" do
+    test "returns parsed results when attachment_links is false" do
       assert Utils.maybe_add_attachments(
                {"test", [], ["tags"]},
                [],
-               true
+               false
              ) == {"test", [], ["tags"]}
     end
 
@@ -589,7 +589,7 @@ defmodule Pleroma.Web.CommonAPI.UtilsTest do
       assert Utils.maybe_add_attachments(
                {"test", [], ["tags"]},
                [attachment],
-               false
+               true
              ) == {
                "test<br><a href=\"SakuraPM.png\" class='attachment'>SakuraPM.png</a>",
                [],