torcontrol: Explicitly request RSA1024 private key

When generating a new service key, explicitly request a RSA1024 one.

The bitcoin P2P protocol has no support for the longer hidden service names
that will come with ed25519 keys, until it does, we depend on the old
hidden service type so make this explicit.

See #9214.

src/torcontrol.cpp

@@ -470,7 +470,7 @@ void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply&
 
         // Finally - now create the service
         if (private_key.empty()) // No private key, generate one
-            private_key = "NEW:BEST";
+            private_key = "NEW:RSA1024"; // Explicitly request RSA1024 - see issue #9214
         // Request hidden service, redirect port.
         // Note that the 'virtual' port doesn't have to be the same as our internal port, but this is just a convenient
         // choice.  TODO; refactor the shutdown sequence some day.