/usr/lib/libpanel-applet-4.so.0 is in libpanel-applet-4-0 1:3.8.0-1ubuntu11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libpanel-applet-4.so.0.1.1
/usr/lib/libpanel-applet-4.so.0.1.1