Fix "gvm" so it doesn't return an error if GVM_NO_GIT_BAK is defined and '.git' directory hasn't been renamed.
Fix "gvm" so it doesn't return an error if GVM_NO_GIT_BAK is defined and
'.git' directory hasn't been renamed.

This is specifically for supporting the current TRAVIS_CI config.

markeissler/gvm2,markeissler/gvm2,markeissler/gvm2