message: Let getCryptoModule detect fallback modules
diff: import { assert } from "@cosmjs/utils";
  +/**
  + * Returns the Node.js crypto module when available and `undefined`
  + * otherwise.
  + *
  + * Detects an unimplemented fallback module from Webpack 5 and returns
  + * `undefined` in that case.
  + */
  export async function getCryptoModule(): Promise<any | undefined> {
  try {
  const crypto = await import("crypto");
  + // We get `Object{default: Object{}}` as a fallback when using
  + // `crypto: false` in Webpack 5, which we interprete as unavailable.
  + if (typeof crypto === "object" && Object.keys(crypto).length <= 1) {
  + return undefined;
  + }
  return crypto;
  } catch {
  return undefined;
  