/usr/lib/x86_64-linux-gnu/libmongo-client.so.0 is in libmongo-client0 0.1.8-3.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmongo-client.so.0.5.0
/usr/lib/x86_64-linux-gnu/libmongo-client.so.0.5.0