Fix vagrant broken after updating to Ruby 2.4
Fix vagrant broken after updating to Ruby 2.4

Ruby got updated in https://github.com/openSUSE/osem/pull/1588,
But there was a repo missed, so Ruby 2.4 can be installed in our Vagrant
machine.

Closes https://github.com/openSUSE/osem/issues/1601

Mob-programmed by @mdeniz, @DavidKang and @Ana06.

SeaGL/osem,AndrewKvalheim/osem,namangupta01/osem,namangupta01/osem,differentreality/osem,hennevogel/osem,differentreality/osem,kormoc/osem,kormoc/osem,bear454/osem,openSUSE/osem,rishabhptr/osem,namangupta01/osem,SeaGL/osem,bear454/osem,AndrewKvalheim/osem,namangupta01/osem,openSUSE/osem,rishabhptr/osem,kormoc/osem,differentreality/osem,bear454/osem,hennevogel/osem,SeaGL/osem,differentreality/osem,kormoc/osem,rishabhptr/osem,rishabhptr/osem,openSUSE/osem,bear454/osem,hennevogel/osem,hennevogel/osem,AndrewKvalheim/osem