freetdm: fix redirection presentation number in X-header

libs/freetdm/mod_freetdm/mod_freetdm.c

@@ -1720,7 +1720,7 @@ ftdm_status_t ftdm_channel_from_event(ftdm_sigmsg_t *sigmsg, switch_core_session
 
 		var_value = ftdm_sigmsg_get_var(sigmsg, "ss7_rdnis_pres_ind");
 		if (!ftdm_strlen_zero(var_value)) {
-			switch_channel_set_variable_printf(channel, "sip_h_X-FreeTDM-RDNIS-Presentation", "%d", channel_caller_data->rdnis.plan);
+			switch_channel_set_variable_printf(channel, "sip_h_X-FreeTDM-RDNIS-Presentation", "%s", var_value);
 		}
 
 		var_value = ftdm_sigmsg_get_var(sigmsg, "ss7_gn_digits");