docs: set rejectUnauthorized based on condition (#5907)

The general guide for hosting the server tells users to set `ssl.rejectUnauthorized` to false for production environments. However, the provided code snippet doesn't check the environment while setting the value. Directly pasting it into `medusa-config.js` will cause database connection attempts made from a development environment to be rejected and you can't even login to the admin account.

The change only sets the ssl property to false if the environment is a non-development one.  ~I got this code suggestion from the Kapa bot on discord so not sure if this is the best way to do this.~ This code is taken from the [configuration docs](https://docs.medusajs.com/development/backend/configurations#database_extra) themselves.

Co-authored-by: Shahed Nasser <27354907+shahednasser@users.noreply.github.com>

www/apps/docs/content/deployments/server/general-guide.md

@@ -39,7 +39,12 @@ In production, it’s recommended to set the [database_extra option](../../devel
 module.exports = {
   projectConfig: {
     // ...
-    database_extra: { ssl: { rejectUnauthorized: false } },
+    database_extra: process.env.NODE_ENV !== "development" ?
+      {
+        ssl: {
+          rejectUnauthorized: false,
+        },
+      } : {},
   },
 }
 ```