message: Fix city culture receding when a nearby fort is built or replaced
diff: @@ -6164,6 +6164,7 @@ void CvPlot::setImprovementType(ImprovementTypes eNewValue)
  pLoopPlot = plotCity3(getX(), getY(), iI);
  if (pLoopPlot != NULL && pLoopPlot->isCity())
  {
  + pLoopPlot->getPlotCity()->setNextCoveredPlot(0, false);
  pLoopPlot->getPlotCity()->updateCultureCosts();
  pLoopPlot->getPlotCity()->updateCoveredPlots(true);
  }
  