message: Fix a crash when using custom rendertargets
  This was introduced recently.
  Fix
diff: @@ -322,7 +322,7 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
  // "+1" to the count for the DEPTH attachment (we don't have stencil for the public RenderTarget)
  for (size_t i = 0; i < RenderTarget::MAX_SUPPORTED_COLOR_ATTACHMENTS_COUNT + 1; i++) {
  auto attachment = currentRenderTarget->getAttachment((RenderTarget::AttachmentPoint)i);
  - if (any(attachment.texture->getUsage() &
  + if (attachment.texture && any(attachment.texture->getUsage() &
  (TextureUsage::SAMPLEABLE | Texture::Usage::SUBPASS_INPUT))) {
  keepOverrideEndFlags |= backend::getTargetBufferFlagsAt(i);
  }
  