cura crashed with SIGSEGV in QQuickItemPrivate::itemToWindowTransform()

[Paweł Drewniak]

I'm not exactly sure what triggered the crash - I was in the initial configuration wizard and I was clicking around the adding printers screen.

```
Description: Ubuntu Hirsute Hippo (development branch)
Release: 21.04

cura:
  Installed: 4.8-3
  Candidate: 4.8-3
  Version table:
 *** 4.8-3 500
        500 http://ie.archive.ubuntu.com/ubuntu hirsute/universe amd64 Packages
        500 http://ie.archive.ubuntu.com/ubuntu hirsute/universe i386 Packages
        100 /var/lib/dpkg/status
```

ProblemType: Crash
DistroRelease: Ubuntu 21.04
Package: cura 4.8-3
ProcVersionSignature: Ubuntu 5.11.0-13.14-generic 5.11.7
Uname: Linux 5.11.0-13-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu61
Architecture: amd64
CurrentDesktop: KDE
Date: Tue Apr 6 01:46:57 2021
ExecutablePath: /usr/bin/cura
InstallationDate: Installed on 2021-04-05 (0 days ago)
InstallationMedia: Kubuntu 21.04 "Hirsute Hippo" - Beta amd64 (20210331.1)
InterpreterPath: /usr/bin/python3.9
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/bin/cura
ProcEnviron:
 LANG=en_IE.UTF-8
 LANGUAGE=en_US:ja
 PATH=(custom, no user)
 SHELL=/bin/bash
 XDG_RUNTIME_DIR=<set>
Python3Details: /usr/bin/python3.9, Python 3.9.2, python3-minimal, 3.9.2-2
PythonDetails: N/A
Signal: 11
SourcePackage: cura
StacktraceTop:
 QQuickItemPrivate::itemToWindowTransform() const () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
 QQuickItemPrivate::windowToItemTransform() const () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
 QQuickItem::mapFromScene(QPointF const&) const () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
 QQuickEventPoint::localizePosition(QQuickItem*) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
 QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem*, QQuickPointerEvent*, bool) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
Title: cura crashed with SIGSEGV in QQuickItemPrivate::itemToWindowTransform()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
separator:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.