MT#3977 Set oubound proxy for priv/shared lines

This is needed for BLF call interceptions, and also for SLA.

assets/linksys-spa5xx-configtemplate.tt

@@ -34,6 +34,7 @@
         <Share_Ext_[% key %]_>[% line.type == "shared" ? "shared" : "private" %]</Share_Ext_[% key %]_>
         <Shared_User_ID_[% key %]_>[% line.type == "shared" ? line.username : "" %]</Shared_User_ID_[% key %]_>
         [% IF line.type == "private" || line.type == "shared" -%]
+	  <Outbound_Proxy_[% key %]_>[% line.domain %]</Outbound_Proxy_[% key %]>
           <Extension_[% key %]_>[% key %]</Extension_[% key %]_>
           <Register_[% key %]_>Yes</Register_[% key %]_>
           <Use_DNS_SRV_[% key %]_>No</Use_DNS_SRV_[% key %]_>