fix confd wait issue

when trying to boot up the registry, it would skip setting etcd
values if anything was set. Because we made some changes to the
cookbook to set some variables to configure the storage backend,
this broke the container. Changing it to set the secretKey if
not present by default fixes the original intention of this
logic.

Author: Matthew Fisher

registry/bin/seed

@@ -1,11 +1,8 @@
 #!/bin/bash
 set -eo pipefail
 
-# if the keyspace already exists, exit early
-etcdctl -C $ETCD ls $ETCD_PATH >/dev/null && exit 0
-
 # seed etcd with default configuration
 etcdctl -C $ETCD set $ETCD_PATH/protocol http
-etcdctl -C $ETCD set $ETCD_PATH/secretKey ${REGISTRY_SECRET_KEY:-`openssl rand -base64 64 | tr -d '\n'`}
+etcdctl -C $ETCD ls $ETCD_PATH/secretKey >/dev/null || etcdctl -C $ETCD set $ETCD_PATH/secretKey ${REGISTRY_SECRET_KEY:-`openssl rand -base64 64 | tr -d '\n'`}
 
-exit 0
+exit 0