kamailio.cfg: set version to 3.3 in the top comments

- GRUU is disabled via registrar modparam to be coherent with the logi
  in config, as GRUU would require lookup for requests within dialog

etc/kamailio.cfg

@@ -1,6 +1,6 @@
 #!KAMAILIO
 #
-# Kamailio (OpenSER) SIP Server v3.2 - default configuration script
+# Kamailio (OpenSER) SIP Server v3.3 - default configuration script
 #     - web: http://www.kamailio.org
 #     - git: http://sip-router.org
 #
@@ -306,6 +306,8 @@ modparam("registrar", "method_filtering", 1)
 #modparam("registrar", "max_contacts", 10)
 # max value for expires of registrations
 modparam("registrar", "max_expires", 3600)
+# set it to 1 to enable GRUU
+modparam("registrar", "gruu_enabled", 0)
 
 
 # ----- acc params -----