message: fix extra unnecessary blit
  we were not reseting the active region after passes that "resolve" the
  guard bands, causing an extra blit to cause that resolving.
diff: @@ -989,6 +989,7 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
  bloomOptions, vignetteOptions);
  // the padded buffer is resolved now
  xvp.left = xvp.bottom = 0;
  + svp = xvp;
  }
  }
  @@ -997,6 +998,7 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
  !hasColorGrading || needsAlphaChannel);
  // the padded buffer is resolved now
  xvp.left = xvp.bottom = 0;
  + svp = xvp;
  }
  if (scaled) {
  mightNeedFinalBlit = false;
  @@ -1010,6 +1012,8 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
  .width = viewport.width, .height = viewport.height,
  .format = colorGradingConfig.ldrFormat });
  }
  + xvp.left = xvp.bottom = 0;
  + svp = xvp;
  }
  }
  