message: access cross-signing callbacks via method
diff: @@ -142,13 +142,13 @@ const onSecretRequested = async function({
  console.log(`CrossSigningManager: Ignoring request from untrusted device ${deviceId}`);
  return;
  }
  - const crossSigning = client._crypto._crossSigningInfo;
  - if (!crossSigning._cacheCallbacks.getCrossSigningKeyCache) return;
  + const callbacks = client.getCrossSigningCacheCallbacks();
  + if (!callbacks.getCrossSigningKeyCache) return;
  if (name === "m.key.self_signing") {
  - const key = await crossSigning._cacheCallbacks.getCrossSigningKeyCache("self_signing");
  + const key = await callbacks.getCrossSigningKeyCache("self_signing");
  return key && encodeBase64(key);
  } else if (name === "m.key.user_signing") {
  - const key = await crossSigning._cacheCallbacks.getCrossSigningKeyCache("user_signing");
  + const key = await callbacks.getCrossSigningKeyCache("user_signing");
  return key && encodeBase64(key);
  }
  console.warn("onSecretRequested didn't recognise the secret named ", name);
  