fix configuration variable names

medusa-config.js

@@ -110,8 +110,8 @@ const modules = {
 
 /** @type {import('@medusajs/medusa').ConfigModule["projectConfig"]} */
 const projectConfig = {
-  jwtSecret: process.env.JWT_SECRET,
-  cookieSecret: process.env.COOKIE_SECRET,
+  jwt_secret: process.env.JWT_SECRET,
+  cookie_secret: process.env.COOKIE_SECRET,
   store_cors: STORE_CORS,
   database_url: DATABASE_URL,
   admin_cors: ADMIN_CORS,