Installer: Make Private network optional

Change-Id: Ic7a2e5250a42dc03de2416b1e2a0d1bbca3f010c
diff --git a/core/installer/values-tmpl/open-project.cue b/core/installer/values-tmpl/open-project.cue
index 8c2da74..1badd08 100644
--- a/core/installer/values-tmpl/open-project.cue
+++ b/core/installer/values-tmpl/open-project.cue
@@ -92,7 +92,7 @@
 					password: "admin"
 					password_reset: false
 					name: "admin"
-					mail: "op-admin@\(global.domain)"
+					mail: "op-admin@\(networks.public.domain)"
 				}
 			}
 			persistence: {