/usr/lib/libmessagecomposer.so.4 is in libmessagecomposer4 4:4.14.10-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libmessagecomposer.so.4.14.16
/usr/lib/libmessagecomposer.so.4.14.16