Update otter-browser to a snapshot.

The last official release was 1.0.01 in january 2019, way too long
ago for a web browser. Many Linux distro's also offer weekly
snapshots of this browser (often calling it 1.0.81). Instead,
bump to a different fake release number; I'm concerned that
1.0.81 might be too high.

Fixes in the tree relate to both QtWebKit and QtWebEngine compatibility,
as well as Qt 5.13 compatibility.

Initial patch by George; I bumped to a different (newer) revision in week 300.

PR: 239203
Reported by: George