usermanual: disable non-existant architecture chapter

Change-Id: I897fb528990d8cf47bd0796603b79bff5fd94bc0
diff --git a/doc/manuals/osmo-remsim-usermanual.adoc b/doc/manuals/osmo-remsim-usermanual.adoc
index 88e3dad..854271a 100644
--- a/doc/manuals/osmo-remsim-usermanual.adoc
+++ b/doc/manuals/osmo-remsim-usermanual.adoc
@@ -20,7 +20,7 @@
 
 //include::./common/chapters/logging.adoc[]
 
-include::{srcdir}/chapters/architecture.adoc[]
+//include::{srcdir}/chapters/architecture.adoc[]
 
 //include::./common/chapters/port_numbers.adoc[]