cluster/crdb: make init job 'idempotent'

This enables its redeployment with a newer crdb image.

Change-Id: If039992674f401af53738c80d22cc2ca2818fe00
diff --git a/cluster/kube/lib/cockroachdb.libsonnet b/cluster/kube/lib/cockroachdb.libsonnet
index 9f206f0..2486570 100644
--- a/cluster/kube/lib/cockroachdb.libsonnet
+++ b/cluster/kube/lib/cockroachdb.libsonnet
@@ -334,7 +334,7 @@
                                 command: [
                                     "/bin/bash",
                                     "-ecx",
-                                    "/cockroach/cockroach init --host=%s.cluster.local:%d" % [cluster.servers[0].service.host, cluster.cfg.portServe],
+                                    "/cockroach/cockroach init --host=%s.cluster.local:%d || true" % [cluster.servers[0].service.host, cluster.cfg.portServe],
                                 ],
                                 volumeMounts: [
                                     {