fix: lock domain purchase if already launched

.env

@@ -42,7 +42,7 @@ CORS_ALLOW_ORIGIN='^https?://(localhost|127\.0\.0\.1)(:[0-9]+)?$'
 ###> symfony/lock ###
 # Choose one of the stores below
 # postgresql+advisory://db_user:db_password@localhost/db_name
-LOCK_DSN=flock
+LOCK_DSN=redis://localhost:6379/lock?lazy=1
 ###< symfony/lock ###
 
 ###> symfony/mailer ###