BUG/MINOR: ssl: free the cafile entries on deinit

The cafile_tree was never free upon deinit, making valgrind and ASAN
complains when haproxy quits.

This could be backported as far as 2.2 but it requires the
ssl_store_delete_cafile_entry() helper from
5daff3c8abc658760a0d0c5fbbc633bfff1afe44.
1 file changed