Checkmk Werk 14335: Fix crash if no icon and an emblem was configured

ID: 14335 Title: Fix crash if no icon and an emblem was configured Component: Multisite Level: 1 Class: Bug fix Version: 2.2.0i1 If you configured e.g. a view with Icon "empty" and an emblem, the GUI crashed, showing the error "TypeError: argument of type 'NoneType' is not iterable" in ~/var/log/web.log.