message: stargate: Fix comparison operator
diff: @@ -3,7 +3,7 @@ import { iavlSpec, ics23, tendermintSpec, verifyExistence, verifyNonExistence }
  import { toAscii, toHex } from "@cosmjs/encoding";
  import { firstEvent } from "@cosmjs/stream";
  import { Client as TendermintClient, Header, NewBlockHeaderEvent, ProofOp } from "@cosmjs/tendermint-rpc";
  -import { arrayContentEquals, assert, isNonNullObject, sleep } from "@cosmjs/utils";
  +import { arrayContentEquals, assert, assertDefined, isNonNullObject, sleep } from "@cosmjs/utils";
  import { Stream } from "xstream";
  type QueryExtensionSetup<P> = (base: QueryClient) => P;
  @@ -233,8 +233,8 @@ export class QueryClient {
  // this must return the header for height+1
  // throws an error if height is 0 or undefined
  private async getNextHeader(height?: number): Promise<Header> {
  - assert(height);
  - if (height == 0) {
  + assertDefined(height);
  + if (height === 0) {
  throw new Error("Query returned height 0, cannot prove it");
  }
  