/etc/ssl/cert.pem is loaded into mem with tls_load_file(3) on local function

/etc/ssl/cert.pem is loaded into mem with tls_load_file(3) on local function
priv_constraint_child() which is called before we reach pledge(2), therefore we
we don't need to unveil(2) that file nor having pledge("rpath") since it was
only required to read that same file.

OK kn@