mod_mam, mod_mam_muc: Check that storagemanager didn't return an instance of the null storage method (Thanks Jonathan)

author: Kim Alvefur <zash@zash.se>
date: Sun, 23 Mar 2014 22:35:27 +0100
parent: 1325:b21236b6b8d8
child: 1399:7fb6b607afd6
--- a/mod_mam/mod_mam.lua	Thu Mar 20 15:55:37 2014 +0100
+++ b/mod_mam/mod_mam.lua	Sun Mar 23 22:35:27 2014 +0100
@@ -34,7 +34,7 @@
 
 local archive_store = "archive2";
 local archive = module:open_store(archive_store, "archive");
-if not archive then
+if not archive or archive.name == "null" then
 	module:log("error", "Could not open archive storage");
 	return
 elseif not archive.find then