crypto: fix public key encryption internals

Coincidentally, the old version works as well since the padding
parameter is never null, but it is semantically incorrect.

PR-URL: #22780
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: tniessen

src/node_crypto.cc

@@ -3890,7 +3890,7 @@ void PublicKeyCipher::Cipher(const FunctionCallbackInfo<Value>& args) {
   bool r = Cipher<operation, EVP_PKEY_cipher_init, EVP_PKEY_cipher>(
       kbuf,
       klen,
-      args.Length() >= 3 && !args[2]->IsNull() ? *passphrase : nullptr,
+      args.Length() >= 4 && !args[3]->IsNull() ? *passphrase : nullptr,
       padding,
       reinterpret_cast<const unsigned char*>(buf),
       len,