Fixes the room size api which returns string result back to client.

resources/prosody-plugins/mod_muc_size.lua

             "there are %s occupants in room", tostring(participant_count));
 	else
 		log("debug", "no such room exists");
+		return 404;
 	end
 
 	if participant_count > 1 then
 		participant_count = participant_count - 1;
 	end
 
-	local GET_response = {
-		headers = {
-			content_type = "application/json";
-		};
-		body = [[{"participants":]]..participant_count..[[}]];
-	};
-	return GET_response;
+	return [[{"participants":]]..participant_count..[[}]];
 end
 
 --- Handles request for retrieving the room participants details
             "there are %s occupants in room", tostring(participant_count));
 	else
 		log("debug", "no such room exists");
+		return 404;
 	end
 
 	if participant_count > 1 then
 		participant_count = participant_count - 1;
 	end
 
-	local GET_response = {
-		headers = {
-			content_type = "application/json";
-		};
-		body = json.encode(occupants_json);
-	};
-	return GET_response;
+	return json.encode(occupants_json);
 end;
 
 function module.load()

resources/prosody-plugins/util.lib.lua

     -- the handler is done.
     local response = event.response;
     local async_func = runner(function (event)
-          response.status_code = handler(event);
-          -- Send the response to the waiting http client.
-          response:send();
+        local result = handler(event);
+        -- if it is a number, it is a status code, else it is the body
+        -- result we will return
+        if (tonumber(result) ~= nil) then
+            response.status_code = result;
+        else
+            response.body = result;
+        end;
+        -- Send the response to the waiting http client.
+        response:send();
     end)
     async_func:run(event)
     -- return true to keep the client http connection open.