Fix a startup issue, where ocserv tries to read "server-cert-secp521r1.pem"...

Fix a startup issue, where ocserv tries to read "server-cert-secp521r1.pem" for vhost "www.example.com" but failed.

Dockerfile

@@ -59,6 +59,7 @@ RUN set -x \
 	&& sed -i 's/192.168.1.2/8.8.8.8/' /etc/ocserv/ocserv.conf \
 	&& sed -i 's/^route/#route/' /etc/ocserv/ocserv.conf \
 	&& sed -i 's/^no-route/#no-route/' /etc/ocserv/ocserv.conf \
+	&& sed -i '/\[vhost:www.example.com\]/,$d' /etc/ocserv/ocserv.conf \
 	&& mkdir -p /etc/ocserv/config-per-group \
 	&& cat /tmp/groupinfo.txt >> /etc/ocserv/ocserv.conf \
 	&& rm -fr /tmp/cn-no-route.txt \