Unset QT_IM_MODULES for qutebrowser; mask at-spi-dbus-bus.service

I'm running into some issues with ibus. I would be fine with japanese
input not working for the moment (it's being worked on, see
https://bugreports.qt.io/browse/QTBUG-58687), but the non-working dead
keys are more of a deal breaker for me. Need to investigate on that.

Also, at-spi-dbus-bus seems to be for accessibility, which I currently
don't need. It's just noise that shows up in the `checkrestart` output
after system upgrades, so mask it.

.local/bin/qutebrowser

@@ -28,6 +28,11 @@ XDG_CONFIG_HOME="${XDG_CONFIG_HOME:-$HOME/.config}"
 XDG_CACHE_HOME="${XDG_CACHE_HOME:-$HOME/.cache}"
 XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"
 
+# Unset input method variable (Qt currently has issues with input methods, see
+# https://bugreports.qt.io/browse/QTBUG-58687 - also, there are issues with dead
+# keys, although that is not consistently reproducible):
+unset QT_IM_MODULE
+
 # Translate options: remove occurrences of -r/--restore from the list of options
 # while saving its argument for later; ignore -R (TODO):
 session=default

.local/etc/systemd/user/at-spi-dbus-bus.service

@@ -0,0 +1 @@
+/dev/null