fix deadlock

FactoryCraft/World.cpp

@@ -70,8 +70,10 @@ void World::update( bool background )
     Entity* player = getCurrentPlayerEntity();
     if( player )
     {
+        renderedWorld->lock();
         for( Dimension* dim : *dimensions )
             dim->removeDistantChunks( { (int)player->getPos().x, (int)player->getPos().y }, this );
+        renderedWorld->unlock();
     }
 }