dialog: fixed adding contact header to REFER generated by dlg_bridge

- reported by Paul Smith

modules/dialog/dlg_transfer.c

@@ -195,7 +195,7 @@ static int dlg_refer_callee(dlg_transfer_ctx_t *dtc)
 	memcpy(hdrs.s+23+dlg_bridge_controller.len+CRLF_LEN+dtc->to.len,
 			CRLF, CRLF_LEN);
 	memcpy(hdrs.s+23+dlg_bridge_controller.len+CRLF_LEN+dtc->to.len+CRLF_LEN,
-			dlg_bridge_controller.s, dlg_bridge_controller.len);
+			dlg_bridge_ref_hdrs.s, dlg_bridge_ref_hdrs.len);
 
 	set_uac_req(&uac_r, &met, &hdrs, NULL, dialog_info, TMCB_LOCAL_COMPLETED,
 				dlg_refer_tm_callback, (void*)dtc);