/usr/lib/x86_64-linux-gnu/libftp.so is in libftp-dev 4.0-1-2+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libftp.so.4.0
/usr/lib/x86_64-linux-gnu/libftp.so.4.0