message: Do not render empty event stream errors
diff: @@ -487,16 +487,18 @@ open class ServerCodegenVisitor(
  }
  if (shape.isEventStream()) {
  - rustCrate.withModule(RustModule.Error) {
  - val symbol = codegenContext.symbolProvider.toSymbol(shape)
  val errors = shape.eventStreamErrors()
  .map { model.expectShape(it.asMemberShape().get().target, StructureShape::class.java) }
  + if (errors.isNotEmpty()) {
  + rustCrate.withModule(RustModule.Error) {
  + val symbol = codegenContext.symbolProvider.toSymbol(shape)
  val errorSymbol = shape.eventStreamErrorSymbol(codegenContext.symbolProvider)
  ServerOperationErrorGenerator(model, codegenContext.symbolProvider, symbol, errors)
  .renderErrors(this, errorSymbol, symbol)
  }
  }
  }
  + }
  /**
  * Generate service-specific code for the model:
  