/usr/lib/x86_64-linux-gnu/owncloud/libocsync.so is in libowncloudsync-dev 1.7.0~beta1+really1.6.4+dfsg-1+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/owncloud/libocsync.so.0