don't add auth headers for in dialog messages

kamailio/auth.cfg

@@ -8,7 +8,7 @@ route[AUTH]
         return;
     }
 
-   if (!is_method("INVITE|MESSAGE|REFER")) {   
+   if (!is_method("INVITE|MESSAGE|REFER")) {
         $avp(auth_allowed) = "true";
         return;
    }
@@ -22,7 +22,7 @@ route[AUTH_HEADERS]
 {
    remove_hf_re("^X-");
 
-   if (!is_method("INVITE|MESSAGE|REFER") || has_totag()) {
+   if (!is_method("INVITE|MESSAGE|REFER")) {
         return;
    }