[REG 5.12] HTML entities in img titles aren't decoded

When looking at the hover text of the image on https://xkcd.com/2123/ it displays "Yachts" correctly on Qt 5.11 and in Chromium, but displays as "Yachts" with Qt 5.12 (e.g. in simplebrowser).

(well, thanks JIRA for interpreting HTML entities I write in plain text mode, even if marked as code, and even if I double-escape them... it displays as & quot ; Yachts & quot ; minus the spaces).