/usr/lib/x86_64-linux-gnu/libQupZilla.so is in libqupzilla-dev 1.6.6-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libQupZilla.so.1.6.3
/usr/lib/x86_64-linux-gnu/libQupZilla.so.1.6.3