Fix segfault if there is no date string.

src/service.c

@@ -1342,7 +1342,11 @@ static gboolean load_message_from_store(const char *service_id,
 	read_status = g_key_file_get_boolean(meta, "info", "read", NULL);
 
     datestr = g_key_file_get_string(meta, "info", "date", NULL);
-    strptime(datestr, "%Y-%m-%dT%H:%M:%S%z", &tm);
+    if (datestr != NULL) {
+        strptime(datestr, "%Y-%m-%dT%H:%M:%S%z", &tm);
+    } else {
+        mms_error("service.c(): There is no date stamp!");
+    }
     
 	data_path = mms_store_get_path(service_id, uuid);
 	if (data_path == NULL)