Humhub 1.14.3 - Module widget crash when clicking on the "Not installed" tab

[marc-farre]

What steps will reproduce the problem?

Go to "Administration" -> "Modules" -> "Not installed" tab.

What is the expected result?

View the not installed modules

What do you get instead?

See https://community.humhub.com/content/perma?id=271074 (personally I cannot reproduce the bug)

Additional info

@yurabakhtin I think the problem is here: https://github.com/humhub/humhub/blob/master/protected/humhub/modules/admin/widgets/Modules.php#L45

Maybe we should replace public $groups; with public $groups = [];?

Q	A
HumHub version	1.14.3

[yurabakhtin]

@luke- @marc-farre Fixed in PR #6560.
I could reproduce the error with disabled module "Marketplace".