unity7 default keybindings are preserved after upgrade and considered as non-default keybindings

[Jean-Baptiste Lallement]

After an upgrade from stock installation of zesty, keybindings defined for unity7 are preserved and considered as non default keybindings.

For example:
in unity 7, ctrl+super+up/down maximizes/restores a window
in gnome-shell super-up/down does the same

but after an upgrade it is still ctrl+super+up/down

I expect that after an upgrade, the default keybindings should be used if the corresponding binding as not been modified before the upgrade.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gsettings-desktop-schemas 3.24.1-1ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-11.12-generic 4.13.1
Uname: Linux 4.13.0-11-generic x86_64
ApportVersion: 2.20.7-0ubuntu1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Sep 21 13:51:49 2017
InstallationDate: Installed on 2013-09-03 (1478 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130902)
PackageArchitecture: all
ProcEnviron:
 TERM=screen-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gsettings-desktop-schemas
UpgradeStatus: No upgrade log present (probably fresh install)

[Jean-Baptiste Lallement (jibel)]

keybindings defined after an upgrade from 17.04