Make eBooks (Smartphone, Tablet, ...) only turn on their light in dar…

…kness (#59261)

* Check local visibility before turning the flashlight app on.

* Add a comment to describe the if clause a bit better

src/iuse.cpp

@@ -9957,7 +9957,8 @@ cata::optional<int> iuse::ebookread( Character *p, item *it, bool t, const tripo
         return cata::nullopt;
     }
 
-    if( !it->active && it->is_transformable() ) {
+    // Only turn on the eBook light, if it's too dark to read
+    if( p->fine_detail_vision_mod() > 4 && !it->active && it->is_transformable() ) {
         const use_function *readinglight = it->type->get_use( "transform" );
         if( readinglight ) {
             readinglight->call( *p, *it, it->active, p->pos() );