/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/qt/proxy_dialog.py is in ubuntu-sso-client-qt 3.0.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/qt/../../../../../../share/pyshared/ubuntu-sso-client/ubuntu_sso/qt/proxy_dialog.py