Stores the room name from the bosh url into the session.

resources/prosody-plugins/mod_auth_token.lua

 	local query = request.url.query;
 
 	if query ~= nil then
-		session.auth_token = query and formdecode(query).token or nil;
-	end
+        local params = formdecode(query);
+        session.auth_token = query and params.token or nil;
+
+        -- The room name from the bosh query
+        session.jitsi_bosh_query_room = params.room;
+    end
 end);
 
 function provider.test_password(username, password)