[DRE-maint] Bug#983346: Update gitlab to 13.7.7 (installation fails - need help)

[Pirate Praveen]

On Tue, 23 Feb 2021 00:47:30 +0530 Pirate Praveen 
<praveen at onenetbeyond.org> wrote:
 > Installing 13.7.7 on a clean system (after purge) works, but fails 
when
 > upgrading from 13.6.7.

What I found out so far is this,

/etc/gitlab/initializers/flipper.rb was obsoleted in 13.6 but we did 
not remove it and that code introduced some changes in db which is now 
causing the error. So I think we will have to revert the changes made 
by this initializer.

And in long term, we should more actively look for obsolete 
initializers like how we check if upstream file list is changed 
upstream.