Remove rpc Sync method from registry handler

registry/proto/registry.proto

@@ -8,7 +8,6 @@ service Registry {
 	rpc Deregister(Service) returns (EmptyResponse) {};
 	rpc ListServices(ListRequest) returns (ListResponse) {};
 	rpc Watch(WatchRequest) returns (stream Result) {};
-        rpc Sync(SyncRequest) returns (SyncResponse) {};
 }
 
 // Service represents a go-micro service
@@ -73,13 +72,6 @@ message WatchRequest {
 	string service = 1;
 }
 
-// SyncRequest to request registry sync
-message SyncRequest {}
-
-message SyncResponse {
-        repeated Service services = 1;
-}
-
 // EventType defines the type of event
 enum EventType {
         Create = 0;