Can't authenticate through AD after 7.9.0 upgrade

Just did an upgrade from 7.8.4 to 7.9.0 using the omnibus package on Ubuntu 14.04. I was authenticating using an Active Directory.

After the upgrade, I can no longer log in using Active Directory. Local account work.

Here is the log I found (in gitlab-rails/production.log):

Started POST "/users/auth/ldapmain/callback" for 127.0.0.1 at 2015-03-24 08:58:33 -0400 Processing by OmniauthCallbacksController#ldapmain as HTML Parameters: {"utf8"=>"<9C><93>", "authenticity_token"=>"long_token", "username"=>"my.username", "password"=>"[FILTERED]"} LDAP search error: Invalid DN Syntax Redirected to https://gitlab.mydomain.com/users/sign_in

I have re-installed the 7.8.4 (same gitlab.rb) and authentication works again.