flaky SttpRestCallTest "too large binary request"

[halotukozak]

SttpRestCallTest "too large binary request" is flaky. Fix made in #1313 is not valid, because the server behaves as espected. A solution should contain the client-side fix

[halotukozak]

Modify the SttpRestCallTest to reproduce the bug

class SttpRestCallTest extends SttpClientRestTest with RestApiTestScenarios {
  test("too large binary request") {
    var i = 0
    while (true) {
      println("i: " + i)
      i += 1
      val future = proxy.binaryEcho(Array.fill[Byte](maxPayloadSize + 1)(5))
      val exception: HttpErrorException = future.failed.futureValue.asInstanceOf[HttpErrorException]
      assert(exception == HttpErrorException.plain(413, "Payload is larger than maximum 1048576 bytes (1048577)"))
    }
  }
}