/usr/lib/libgtkhtml-3.14.so is in libgtkhtml3.14-dev 1:3.32.2-0ubuntu4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libgtkhtml-3.14.so.19.1.1
/usr/lib/libgtkhtml-3.14.so.19.1.1