/usr/lib/libgconfmm-2.6.so is in libgconfmm-2.6-dev 2.28.3-0ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libgconfmm-2.6.so.1.0.6
/usr/lib/libgconfmm-2.6.so.1.0.6