Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 ID:20190510214931

Description:

The new about:addons contains a message what extensions enabled in private windows can do (addon-detail-private-browsing-help in toolkit/toolkit/about/aboutAddons.ftl). This message is normally shown for add-ons, which you can enable or disable in private windows. For themes it's not there, as not applicable.

The message is however shown for plugins and dictionaries even though there is no option to enable/disable them.

STR:

1. Enable new about:addons.
2. Open the tab with extensions or dictionaries.
3. Double-click any of them or open more options via the three-dots menu.
4. See the plugin/dictionary info and options at the bottom, right under the automatic update prefrences.

Expected behaviour:
The message should be shown only together with the preference, which means for add-ons only (not for themes, plugins nor dictionaries).