have session manager check session config for sending notifications on unbinds.

src/main/java/io/kamax/mxisd/session/SessionManager.java

@@ -234,8 +234,10 @@ public class SessionManager {
         }
 
         log.info("Unbinding of {} {} to {} is accepted", tpid.getMedium(), tpid.getAddress(), mxid.getId());
+        if (cfg.getSession().getPolicy().getUnbind().shouldNotify()) {
             notifMgr.sendForUnbind(tpid);
         }
+    }
 
     private void checkAuthorization(String auth, JsonObject reqData) {
         if (!auth.startsWith("X-Matrix ")) {