kube: clean up SimpleIngress

Rename `target_service` to `target` to mirror Service's `target`; rename `extra_paths` to `extraPaths` to follow the camelCase convention used everywhere except for a few places in kube.upstream (assumed to be a mistake)

Change-Id: Icfcb70ef889e3359bf0391c465034817f4b70cce
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1809
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/app/onlyoffice/prod.jsonnet b/app/onlyoffice/prod.jsonnet
index dfd20a9..d1ea875 100644
--- a/app/onlyoffice/prod.jsonnet
+++ b/app/onlyoffice/prod.jsonnet
@@ -75,7 +75,7 @@
 
         ingress: ns.Contain(kube.SimpleIngress("office")) {
             hosts:: [cfg.domain],
-            target_service:: top.svc,
+            target:: top.svc,
         },
 
         // Needed because the documentserver runs its own supervisor, and: