languages.en.build_search_index = true doesn't work if build_search_index is false for the default language

[salif]

Bug Report

Environment

Zola version: 0.19.2

Expected Behavior

I want to enable search only for english language because default language Bulgarian bg is not supported.

Current Behavior

Neither search_index.en.js nor elasticlunr.min.js file is generated.

Step to reproduce

This is in my config.toml file:

default_language = "bg"
build_search_index = false

[languages.en]
build_search_index = true