lock returns host and owner

other/java/client/src/main/proto/filer.proto

@@ -452,8 +452,9 @@ message LockRequest {
 }
 message LockResponse {
     string renew_token = 1;
-    string moved_to = 2;
-    string error = 3;
+    string lock_owner = 2;
+    string lock_host_moved_to = 3;
+    string error = 4;
 }
 message UnlockRequest {
     string name = 1;