If loading the CA certificates at startup had failed, the syslogd

If loading the CA certificates at startup had failed, the syslogd
child tried to load the default CA file when it was connecting to
a TLS server.  The latter has never worked as the child is chrooted
to /var/empty.  Set the CA storage to an empty string to avoid this
behavior.  As a benefit pledge "rpath" can be removed.
OK benno@