Don't enable groundcover for non-default worldspaces (#7692)

apps/openmw/mwrender/renderingmanager.cpp

@@ -1455,7 +1455,7 @@ namespace MWRender
         RenderingManager::WorldspaceChunkMgr newChunkMgr;
 
         const float lodFactor = Settings::terrain().mLodFactor;
-        const bool groundcover = Settings::groundcover().mEnabled;
+        const bool groundcover = Settings::groundcover().mEnabled && worldspace == ESM::Cell::sDefaultWorldspaceId;
         const bool distantTerrain = Settings::terrain().mDistantTerrain;
         const double expiryDelay = Settings::cells().mCacheExpiryDelay;
         if (distantTerrain || groundcover)