Oops, don't need to use embargoes if the resolution is on the same machine as…

Oops, don't need to use embargoes if the resolution is on the same machine as the promise, since the network path of calls is unchanged in that case.

c++/src/capnp/rpc.c++

@@ -953,9 +953,13 @@ private:
     mutable bool receivedCall = false;
 
     void resolve(kj::Own<const ClientHook> replacement) {
-      if (__atomic_load_n(&receivedCall, __ATOMIC_RELAXED)) {
-        // There were calls to the old inner.  We have to send it an embargo and temporarily
-        // delay resolution.
+      if (replacement->getBrand() != this &&
+          __atomic_load_n(&receivedCall, __ATOMIC_RELAXED)) {
+        // The new capability is hosted locally, not on the remote machine.  And, we had made calls
+        // to the promise.  We need to make sure those calls echo back to us before we allow new
+        // calls to go directly to the local capability, so we need to set a local embargo and send
+        // a `Disembargo` to echo through the peer.
+
         auto message = connectionState->connection->newOutgoingMessage(
             messageSizeHint<rpc::Disembargo>() + sizeInWords<rpc::MessageTarget>() +
             sizeInWords<rpc::PromisedAnswer>());