fix: speakerstats_component, attempt to index (a nil value)

resources/prosody-plugins/mod_speakerstats_component.lua

@@ -41,6 +41,11 @@ function on_message(event)
             return false;
         end
  
+        if not room.speakerStats then
+            log("warn", "No speakerStats found for %s", roomAddress);
+            return false;
+        end
+
         local roomSpeakerStats = room.speakerStats;
         local from = event.stanza.attr.from;
 
@@ -188,6 +193,10 @@ function occupant_leaving(event)
         return;
     end
  
+    if not room.speakerStats then
+        return;
+    end
+
     local occupant = event.occupant;
 
     local speakerStatsForOccupant = room.speakerStats[occupant.jid];