Remove allow_to_discover from appInstance

PR #46 accidently added allow_to_discover field to app_instance
which was removed in #52

Not deprecating field number 25 (allow_to_discover) because we haven't
had released EVE with this API yet, so we don't have to do this

Signed-off-by: Pavel Abramov <uncle.decart@gmail.com>

proto/config/appconfig.proto

@@ -158,8 +158,6 @@ message AppInstanceConfig {
   // contains the encrypted userdata
   org.lfedge.eve.common.CipherBlock cipherData = 13;
 
-  // Deprecated 14
-
   // The static IP address assigned on the NetworkAdapter which App Container
   // stats collection uses. If the 'collectStatsIPAddr' is not empty and valid,
   // it enables the container stats collection for this App.
@@ -210,10 +208,6 @@ message AppInstanceConfig {
   // PatchEnvelopeRef is used to track all patch envelopes used by the app instance
   PatchEnvelopeRef patchRef = 23;
 
-  // allow AppInstance to discover other AppInstances
-  // attached to its network instances
-  bool allow_to_discover = 25;
-
   // This edge-node UUID for the Designate Node for the Application
   string designated_node_id = 26;
 }