Fix login processor to use absolute url redirects for mgr

Allows mgr deployments on subdomains, https-only configurations, etc. - uses url_scheme+http_host+manager_url
Fix login processor to use absolute url redirects for mgr

Merge remote-tracking branch 'opengeek/mgr-login-redirect-fix' into release-2.2

* opengeek/mgr-login-redirect-fix:
  Fix login processor to use absolute url redirects for mgr

Conflicts:
	core/docs/changelog.txt