Increase IconImageCache max size to 512

 map.html

@@ -18,6 +18,6 @@
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v5.3.0/build/ol.js" integrity="sha384-iQkGyyH4ioz3m+maM3s9MX1Oq67mACa4B9Z3ovUv3Sv37LJ96fx3WnZfLoiC3Wfl" crossorigin="anonymous"></script>
<script tyle="text/javascript" src="lang_pl.js?v3" id="lang_script"></script>
<script tyle="text/javascript" src="common.js?v5"></script>
<script tyle="text/javascript" src="map.js?v8"></script>
<script tyle="text/javascript" src="map.js?v9"></script>
</body>
</html>

 map.js

@@ -783,6 +783,8 @@
        }),
    });
    
    ol.style.IconImageCache.shared.setSize(512);
	
    map = new ol.Map({
        target: 'map',
        layers: [