/usr/lib/x86_64-linux-gnu/libcurl-gnutls.so.4 is in libcurl3-gnutls 7.22.0-3ubuntu4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcurl-gnutls.so.4.2.0
/usr/lib/x86_64-linux-gnu/libcurl-gnutls.so.4.2.0