[Default-Configuration] Force sip subscription requests to require authentication.

conf/insideout/sip_profiles/internal.xml

@@ -129,6 +129,8 @@
     <!-- add a ;received="<ip>:<port>" to the contact when replying to register for nat handling -->
     <!--<param name="NDLB-received-in-nat-reg-contact" value="true"/>-->
     <param name="auth-calls" value="$${internal_auth_calls}"/>
+    <!-- Force subscription requests to require authentication -->
+    <param name="auth-subscriptions" value="true"/>
     <!-- Force the user and auth-user to match. -->
     <param name="inbound-reg-force-matching-username" value="true"/>
     <!-- on authed calls, authenticate *all* the packets not just invite -->