* Fix redirect on login for instances
On instances where base_url has been set for use behind a reverse proxy, logins are incorrectly redirected.
This happens because REQUEST_URI is set by the proxy:
1. librenms has base_url set to http://site.com/nms/
2. Browser requests http://site.com/nms/
3. nginx reverse proxies /nms/ to librenms at http://somehost:1234/
4. librenms sees REQUEST_URI as "/"
5. librenms logs the user in, but sends "Location: /" to the browser. This redirects to the wrong location.
To resolve, concatenate REQUEST_URI (which is relative) to base_url. As base_url is slash-terminated, crop the trailing slash. This should have no effect on users with default settings and will correctly redirect instances behind reverse proxies.
* I agree to the conditions of the Contributor Agreement contained in doc/General/Contributing.md.
* Adding comment explaining redirect logic on login
* Use rtrim instead of substr
02017068e7