Set "zpl_managed=True" on existing device classes installed pre 2.1.0
Attribute "zpl_managed" was not set on device classes prior to 2.1.0. The attribute is checked prior to device class removal during ZenPack uninstallation, so this check fails unless ZenPackLib 2.1.0 is installed prior to fresh installation of any dependent ZenPacks. Since the check fails, device classes can be left behind, which means that devices within them will also be left undeleted. This in turn can cause Zope object/model catalog issues since class dependency removal will break these objects.
Attribute "zpl_managed" was not set on device classes prior to 2.1.0. The attribute is checked prior to device class removal during ZenPack uninstallation, so this check fails unless ZenPackLib 2.1.0 is installed prior to fresh installation of any dependent ZenPacks. Since the check fails, device classes can be left behind, which means that devices within them will also be left undeleted. This in turn can cause Zope object/model catalog issues since class dependency removal will break these objects.