etc/kamailio.cfg: set load_backends to 1 for permissions module

- the config uses only address table

etc/kamailio.cfg

@@ -420,7 +420,7 @@ modparam("auth_db", "use_domain", MULTIDOMAIN)
 # ----- permissions params -----
 #!ifdef WITH_IPAUTH
 modparam("permissions", "db_url", DBURL)
-modparam("permissions", "db_mode", 1)
+modparam("permissions", "load_backends", 1)
 #!endif
 
 #!endif