fix: remove problematic errorTileUrl to resolve tile loading errors

The errorTileUrl was set to a base64 data URL of a transparent 1x1 PNG,
which caused browsers to fail when trying to use it as a tile replacement.
Removing this option allows Leaflet to handle tile errors with its
default behavior, which is more robust and prevents console errors.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

assets/js/map.ts

@@ -297,8 +297,8 @@ let MapAPRSMap = {
         keepBuffer: 2,
         updateWhenZooming: false,
         updateInterval: 200,
-        errorTileUrl:
-          "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=",
+        // Remove errorTileUrl to let Leaflet handle tile errors gracefully
+        // errorTileUrl causes issues with some browsers when using data URLs
       });
 
       // Add event handler for tile errors with retry logic