prosody: Enable mod_measure_active_users

This allows an operator (via Prometheus, or eventually the web portal) to keep
tabs on how many people are using the server, e.g. to assist with capacity
planning. This will become more important once we allow user-to-user account
invitations.

ansible/files/prosody.cfg.lua

@@ -127,6 +127,7 @@ modules_enabled = {
 
 	-- Monitoring & maintenance
 		"measure_process";
+		"measure_active_users";
 }
 
 registration_watchers = {} -- Disable by default

ansible/snikket.yml

@@ -9,7 +9,7 @@
       package: "prosody-trunk"
       build: "1544"
     prosody_modules:
-      revision: "eb63890ae8fc"
+      revision: "1132f2888cd2"
   tasks:
     - import_tasks: tasks/prosody.yml
     - import_tasks: tasks/supervisor.yml

ansible/tasks/prosody.yml

@@ -125,6 +125,7 @@
     - mod_watch_spam_reports
     - mod_isolate_host
     - mod_muc_auto_reserve_nicks
+    - mod_measure_active_users
 
 - name: Enable wanted modules (snikket-modules)
   file: