adds git terminal prompt env var to application rb

changelogs/unreleased/24187-set-git-terminal-prompt-env-var-in-initializer.yml

+---
+title: Set GIT_TERMINAL_PROMPT env variable in initializer
+merge_request: 10372
+author:

config/application.rb

@@ -150,6 +150,7 @@ module Gitlab
     # This is needed for gitlab-shell
     ENV['GITLAB_PATH_OUTSIDE_HOOK'] = ENV['PATH']
+    ENV['GIT_TERMINAL_PROMPT'] = '0'
     config.generators do |g|
       g.factory_girl false