bug fix race condition while installing VBoxAdditions
bug fix race condition while installing VBoxAdditions

kraksoft/vagrant-box,xezpeleta/vagrant-debian-jessie-64,dotzero/vagrant-debian-jessie-64,wummel/vagrant-virtualbox-debian-base,jstuyts/vagrant-jessie-minimal-amd64-customizable,Gasol/vagrant-debian-jessie-64,shtouff/vagrant-debian-jessie-64,dforsber-p/vagrant-debian-jessie-64,code-kitchen/vagrant-debian-jessie-64,crazycode/vagrant-debian-wheezy-64,nvtkaszpir/vagrant-box,ginas/vagrant-debian-wheezy-64