add hmac_key configured field

src/invidious.cr

@@ -58,6 +58,7 @@ end
 alias IV = Invidious
 
 CONFIG   = Config.load
+HMAC_KEY_CONFIGURED = CONFIG.hmac_key != nil
 HMAC_KEY = CONFIG.hmac_key || Random::Secure.hex(32)
 
 PG_DB       = DB.open CONFIG.database_url

src/invidious/jobs/statistics_refresh_job.cr

@@ -17,6 +17,7 @@ class Invidious::Jobs::StatisticsRefreshJob < Invidious::Jobs::BaseJob
     "metadata" => {
       "updatedAt"              => Time.utc.to_unix,
       "lastChannelRefreshedAt" => 0_i64,
+      "hmacKeyConfigured"      => HMAC_KEY_CONFIGURED,
     },
   }