Update push.rb
Update push.rb

https://github.com/mitchellh/vagrant/issues/5570

When uploading from Windows to Linux, the Windows filepath was added to the Linux path.
signed8bit/vagrant,vamegh/vagrant,justincampbell/vagrant,lukebakken/vagrant,lukebakken/vagrant,mwrock/vagrant,PatrickLang/vagrant,crashlytics/vagrant,mkuzmin/vagrant,jtopper/vagrant,PatOShea/vagrant,benh57/vagrant,tomfanning/vagrant,TheBigBear/vagrant,aneeshusa/vagrant,carlosefr/vagrant,mwrock/vagrant,sni/vagrant,crashlytics/vagrant,Endika/vagrant,chrisroberts/vagrant,kamigerami/vagrant,marxarelli/vagrant,chrisroberts/vagrant,benizi/vagrant,Chhed13/vagrant,invernizzi-at-google/vagrant,bryson/vagrant,justincampbell/vagrant,jtopper/vagrant,bryson/vagrant,Endika/vagrant,tomfanning/vagrant,bdwyertech/vagrant,petems/vagrant,sax/vagrant,jtopper/vagrant,chrisroberts/vagrant,kamigerami/vagrant,krig/vagrant,gitebra/vagrant,sni/vagrant,benh57/vagrant,Endika/vagrant,tomfanning/vagrant,bshurts/vagrant,kamigerami/vagrant,signed8bit/vagrant,krig/vagrant,invernizzi-at-google/vagrant,Chhed13/vagrant,vamegh/vagrant,lonniev/vagrant,carlosefr/vagrant,bdwyertech/vagrant,PatOShea/vagrant,aneeshusa/vagrant,taliesins/vagrant,sax/vagrant,aneeshusa/vagrant,PatOShea/vagrant,bshurts/vagrant,benh57/vagrant,lonniev/vagrant,bdwyertech/vagrant,aneeshusa/vagrant,kamazee/vagrant,kamazee/vagrant,kamazee/vagrant,bdwyertech/vagrant,mitchellh/vagrant,vamegh/vagrant,johntron/vagrant,signed8bit/vagrant,justincampbell/vagrant,mwrock/vagrant,kamazee/vagrant,PatOShea/vagrant,crashlytics/vagrant,carlosefr/vagrant,lonniev/vagrant,mkuzmin/vagrant,sni/vagrant,sax/vagrant,marxarelli/vagrant,petems/vagrant,mkuzmin/vagrant,lukebakken/vagrant,petems/vagrant,lukebakken/vagrant,petems/vagrant,aaam/vagrant,aaam/vagrant,mitchellh/vagrant,taliesins/vagrant,bshurts/vagrant,bshurts/vagrant,TheBigBear/vagrant,bryson/vagrant,Chhed13/vagrant,Chhed13/vagrant,sax/vagrant,tomfanning/vagrant,benizi/vagrant,johntron/vagrant,taliesins/vagrant,marxarelli/vagrant,marxarelli/vagrant,PatrickLang/vagrant,TheBigBear/vagrant,invernizzi-at-google/vagrant,mwrock/vagrant,vamegh/vagrant,justincampbell/vagrant,chrisroberts/vagrant,aaam/vagrant,taliesins/vagrant,mitchellh/vagrant,signed8bit/vagrant,benizi/vagrant,crashlytics/vagrant,benizi/vagrant,bryson/vagrant,mkuzmin/vagrant,sni/vagrant,krig/vagrant,TheBigBear/vagrant,mitchellh/vagrant,benh57/vagrant,Endika/vagrant,johntron/vagrant,invernizzi-at-google/vagrant,jtopper/vagrant,johntron/vagrant,PatrickLang/vagrant,aaam/vagrant,gitebra/vagrant,gitebra/vagrant,krig/vagrant,lonniev/vagrant,carlosefr/vagrant,gitebra/vagrant,PatrickLang/vagrant,kamigerami/vagrant