⏪ revert "🚧 temporarily hide RVI4S1 index"

This reverts commit 1da51bc3114daa423e9ab9408d34881a72323471.

src/app/calculator/calculator.service.ts

@@ -19,7 +19,7 @@ import {imageWmsTLayer, imageWmsTSource} from './image-wms-t-layer';
 /**
  * Set of precalculated indices
  */
-const INDICES_PRE_FLIGHT = ['EVI', 'NDVI'] as const; //FIXME: , 'RVI4S1'
+const INDICES_PRE_FLIGHT = ['EVI', 'NDVI', 'RVI4S1'] as const;
 /**
  * Set of indices which are calculated on the fly
  */