Fix httpd example config

Fix httpd example config

A server configuration yields multiple struct server_config in the
env->sc_servers queue: an actual server ("parent") and one for each
location directive in httpd.conf.  In parent_configure(), the parents
are configured first, then the corresponding locations.

parse.y r1.118 kills the parent if an error is encountered on loading
the TLS keypairs but leaves the locations in the sc_servers queue.
When running the default config without TLS keys already in place, this
then leads to the self-explanatory "invalid location" error message. Its
intention is to indicates the unexpected situation that config_setserver()
encounters a location without an associated server.

Fix this by not only destroying the parent but also removing all of its
locations.

ok jsing