www/qutebrowser: update to 1.13.1

Fixed
-With Qt 5.14, shared workers are now disabled. This works around a crash in
QtWebEngine on certain sites (like the Epic Games Store or the Unreal Engine
page).
-When a window is closed, the tab it contains are now correctly shut down
(closing e.g. any dialogs which are still open for those tabs).
-The Qt 5.15 session workaround now loads the correct (rather than the latest)
page when :back was used before saving a session.
-In certain situations on Windows, qutebrowser fails to find the username of
the user launching qutebrowser (most likely due to a bug in the application
launching it). When this happens, an error is now displayed instead of
crashing.
-Certain autoconfig.yml with an invalid structure could lead to crashes,
which are now fixed.
-Generating docs with asciidoc2html.py (e.g. via mkvenv.py) now works
correctly without Pygments being installed system-wide.
-Ever since Qt 5.9, when input.mouse.rocker_gestures was enabled, the
context menu still was shown when clicking the right mouse button, thus
preventing the rocker gestures. This is now fixed.
-Clicking the inspector switched from existing modes (such as passthrough) to
normal mode since v1.13.0. Now insert mode is only entered when the inspector
is clicked in normal mode.
-Pulseaudio now shows qutebrowser's audio streams as qutebrowser correctly,
rather than showing them as Chromium with some Qt versions.
-If :help was called with a deprecated command (e.g. :help :inspector),
the help page would show despite deprecated commands not being documented.
This now shows an error instead.
-The qute-lastpass userscript now filters out duplicate entries with
--merge-candidates.

(pin)