I’m sorry you didn’t find any satisfaction in this plugin. If you want to remove it just follow the steps :
Before removing the plugin, stop Redmine!
root$ su - redmine
redmine$ cd REDMINE_ROOT
redmine$ bundle exec rake redmine:plugins:migrate RAILS_ENV=production NAME=redmine_git_hosting VERSION=0
redmine$ rm -rf REDMINE_ROOT/plugins/redmine_git_hosting