Revert "add Vim undo files to .gitignore"
Revert "add Vim undo files to .gitignore"

This reverts commit f4f16c381bed1cebc38710e33f6f2433dd933083.

UKHomeOffice/vcloud-launcher,UKHomeOffice/vcloud-launcher,gds-operations/vcloud-launcher,gds-operations/vcloud-launcher,gds-operations/vcloud-launcher,UKHomeOffice/vcloud-launcher