Checkmk Werk 7778: Fix sorting views by inventory columns

ID: 7778 Title: Fix sorting views by inventory columns Component: Multisite Level: 1 Class: Bug fix Version: 1.7.0i1 Views that sorted their rows by inventory columns could not be rendered in 1.6.0b1. They always showed an exception like this: <tt>TypeError: <lambda>() takes exactly 2 arguments (3 given)</tt>.