/usr/lib/x86_64-linux-gnu/libxmlrpc_client.so is in libxmlrpc-core-c3-dev 1.33.14-0.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libxmlrpc_client.so.3
/usr/lib/x86_64-linux-gnu/libxmlrpc_client.so.3