[SofrwareUpdater] crash on clicking Cancel in Package problems window

[diver]

I reproduced it only once, next tries didn't trigger this crash again.

Debug information for team /boot/system/apps/SoftwareUpdater (14023):
CPU(s): 2x Intel Core™ i7-3635QM
Memory: 1.49 GiB total, 679.82 MiB used
Haiku revision: hrev54798 Dec 18 2020 07:28:18 (x86_64)

Active Threads:
	thread 14023: SoftwareUpdater (main)
	thread 14029: w>SoftwareUpdater 
	thread 14041: team 14023 debug task 
	thread 14027: WorkingLooper 
		state: Exception (Segment violation)

		Frame		IP			Function Name
		-----------------------------------------------
		00000000	00000000	? 
			Unable to retrieve disassembly for IP 0: address not contained in any valid image.
		0x7fa21c952a60	0x21968399ad4	ProblemWindow::Go(BPackageKit::BSolver*, std::set<BPackageKit::BSolverPackage*, std::less<BPackageKit::BSolverPackage*>, std::allocator<BPackageKit::BSolverPackage*> > const&, std::set<BPackageKit::BSolverPackage*, std::less<BPackageKit::BSolverPackage*>, std::allocator<BPackageKit::BSolverPackage*> > const&) + 0x114 
		0x7fa21c952af0	0x21968395c5b	UpdateManager::HandleProblems() + 0x7b 
		0x7fa21c952b10	0xb8413a267a	BPackageKit::BManager::BPrivate::BPackageManager::_HandleProblems() + 0x1a 
		0x7fa21c952b30	0xb8413a5345	BPackageKit::BManager::BPrivate::BPackageManager::FullSync() + 0x25 
		0x7fa21c952b90	0x21968395450	UpdateAction::Perform(update_type) + 0x60 
		0x7fa21c952be0	0x11dbad21496	BLooper::task_looper() + 0x266 
		0x7fa21c952c00	0x11dbad1fbbb	BLooper::_task0_(void*) + 0x1b 
		0x7fa21c952c20	0x117d006a2e7	thread_entry + 0x17 
		00000000	0x7ffb66301260	commpage_thread_exit + 0