convert: svn: ensure leading / is removed from paths in _find_children (broken in 2bd996d0aaf8)
adding ab renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3a renamed from b:9a263dd772e0159ddfa70fb8a448bb6c7ec8c69f% test with --revb renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3