Update databases.md

王权利请求将github/fork/weiweijeff/patch-1合并到master

Created by: weiweijeff

in installation.md file, it uses 'gitlab'@'localhost',if we creat 'git'@'localhost' here,we will get rake aborted! Access denied for user 'gitlab'@'localhost' (using password: YES) when we do sudo -u git -H bundle exec rake gitlab:setup RAILS_ENV=production

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