cta-dcache: drop 'transport' field from DeleteRequest

cta-dcache/grpc-proto/protobuf/cta_rpc.proto

@@ -65,9 +65,8 @@ message RetrieveRequest {
 message DeleteRequest {
   cta.common.Service instance = 1;  // client instance ID
   cta.eos.Client cli = 2;      // requester information
-  cta.eos.Transport transport = 3;      // IO, error and success endpoints
-  FileInfo file = 4;      // files' metadata
-  uint64 archiveId = 5; // tape system unique file ID
+  FileInfo file = 3;      // files' metadata
+  uint64 archiveId = 4; // tape system unique file ID
 }
 
 service CtaRpc {