Fix assertions in KDescendantsProxyModel
Remove assertions in kdescendantsproxymodel.cpp
that will make the program crash when the model is empty.
Note: if hasChildren
returns true, it doesn't mean that rowCount
for the same index must be >0.
For example, KDirModel's hasChildren
returns true for directories with >=1 children, but its rowCount
doesn't list
the children and just returns 0 if they weren't already listed.
Bug: 452043