Add exception for git pull

Make the ruby-build folder safe to pull from even when its not owned by root

Author: somewatson

root/etc/s6-overlay/s6-rc.d/init-mod-code-server-rbenv-install/run

@@ -20,6 +20,7 @@ if [ -d /config/.rbenv/plugins/ruby-build ]; then
         /config/.rbenv
 
     echo 'Upgrading ruby-build plugin'
+    git config --global --add safe.directory /config/.rbenv/plugins/ruby-build
     git -C /config/.rbenv/plugins/ruby-build pull
 else
     echo 'Cloning ruby-build plugin repo'