Update .env.testing

.env.testing

@@ -7,7 +7,6 @@ APP_URL=https://pixelfed.dev
 APP_DOMAIN="pixelfed.dev"
 ADMIN_DOMAIN="pixelfed.dev"
 SESSION_DOMAIN="pixelfed.dev"
-SESSION_SECURE_COOKIE=true
 TRUST_PROXIES="*"
 
 LOG_CHANNEL=stack