Remove image optimisation logic for areas with icons that have already been optimised.

[dadofsambonzuki]

We are slowly migrating area icons to 256x256 PNGs with a standardised locationas follows:

https://static.btcmap.org/images/areas/<id>.png

The Web App currently routes all area icon requests through Netlify's image optimisation service:

https://btcmap.org/.netlify/images?url=https://static.btcmap.org/images/areas/46.png&fit=cover&w=256&h=256

Any icon_url that has the relative path /images/areas/ does not need to go through this service as it is already optimised.